I am publishing Salem Coffee Roasting Manual 4thEdition here. I can’t speak English at all, so I just added a minimum of work to this sentence translated by Google Translate (I hope there are no parts that are arbitrarily omitted or inappropriate translations) Also, I wrote this book in Japan’s environment, so I don’t think this manual applies to all people in English-speaking countries, But for example, there is a single drum roaster that evolved from the American Royal roaster just like Fuji Royal from the San Francisco roaster, so I think it will be useful sometimes. Furthermore, there is no change in the fact that cracking due to lignin melting of bean cell wall occurs at 200°C Fahrenheit 392 degrees exactly and second cracking occurs at 220°C Fahrenheit 428 degrees. I pray from Japan that this book will make your roasting more wonderful！
Salem Coffee Roasting Manual 4th
Editionをここに公開します。 私は全く英語が喋れないのでこの文章も Google 翻訳で翻訳したものに最低限度の手を加えただけです（勝手に省略されている部分や不適切な翻訳がなければいいのですが）また、私は日本の環境下でこの本をかいたので英語圏の方々にこのマニュアルがすべて当てはまるとは思いません、 しかし例えばサンフランシスカン焙煎機のようなフジローヤルと同じようにアメリカのロイヤル焙煎機から発展した一重ドラム焙煎機もあるので役に立つこともあると思います、さらに200℃華氏392度丁度豆の細胞壁のリグニンの溶融によるクラックが、220℃華氏428度で2回めのクラックが起こることに変わりはありません。 この本が皆さんの焙煎をより素晴らしいものにすることを日本から祈っています！
Salaam Kaffi roasting manual
First edition 2022/01/13 Second edition 2022/08/13 Third edition 2022/09/07 Fourth edition 2023/04/20
table of contents
0 Preface
1 Purpose of this document
2 Outline of roasting method
3 Progress of roasting
4 An example of roasting practice ~ In the case of a domestic semi-hot air roasting machine ~
5 Difference between thermometer and bean temperature
6 Data collection and profile creation
7 Features of the hot air roasting machine
8 Exhaust adjustment
9 Various roasting methods
10 Roasting failures and countermeasures
11 About raw beans
12 Preservation and blending of roasted beans
13 Hygiene management and accidents
14 machinery
15 Manufacturer information and reference materials
16 At the end
0 Preface
As a unique hypothesis in this book
1 When coffee beans reach 180°C, 200°C, 220°C, or 230°C due to the thermal decomposition or melting of cell wall constituents, cracking usually occurs twice (up to three times).
2. The taste changes when the ratio of conductive heat and convective heat of the roaster changes.
3. For these reasons, the roasting and taste are different between a single drum roaster and a double drum roaster.。
I claim the above.
1 Purpose of this document
This book is a roasting manual for individual coffee bean shops that I personally wrote for myself.
If the taste of coffee is a perfect score of 1000, the taste is created by the taste of the raw beans made by the farmer: 100 x roasting 10 x extraction 1 = 1000 points. Making, cultivating, harvesting, producing, transporting, roasting, and extracting. In these processes, we are involved in the final roasting and selling, so we do not waste the efforts of so many people. To improve the lives of everyone involved in coffee, we must make it as sellable as possible, especially for farmers in poorer countries, without having to touch cannabis, poppies and carts. I hope that the free publication of this book will help.
*From the 4th edition of this book, we stopped the page layout assuming printing on A4 paper and recreated it as a web page. Since version control will not be done in the future, this page is always the latest version.
2 Outline of roasting method
In this book, the heat source for individual stores is gas fire.Small domestic drum type semi-hot air roasting machinecentered, thenhot airI will explain how to roast as an example.
in the Japanese classificationSemi hot airis a method of applying heat to the beans by both conduction heat from the drum and convection heat from the hot air.
hot airheats the beans with hot air,direct firegives hot air from the fire directly in a perforated drum,
By the way, even if it is called a semi-hot air type for the Japanese market, it is actually a double drum that blocks the conduction heat.A double-drum roasting machine similar to a hot-air typeThere are many
The definition of hot-air roasting differs depending on the country and manufacturer.In Japan, drum-type indirect hot-air roasters and fluidized-bed roasters, which have separate heat sources, are both called hot-air roasters.In this book, the double-drum roaster, which strongly relies on convection heat, is called the hot-air type, and the single-drum roaster, which is often designed in Japan with emphasis on conductive heat, is called the semi-hot-air type.
Each method has a different rate of temperature rise and fall, ease of burning, and taste.
The things that can be adjusted during roasting are the input amount and moisture content on the bean side, but on the roasting machine side, the heat power, wind force, and time of the roaster can be adjusted. Predetermined reference time and temperature rise curve
We plan a roast profile (called a roasting curve or roast graf), determine the balance between the input amount and wind force before roasting, and concentrate on adjusting the gas pressure.
With a Japanese semi-hot air roaster, you can adjust the heat applied to the beans by changing the gas pressure and air volume, but you can manually open and close the exhaust valve during roasting to stabilize the calories given to the beans. is difficult and reproducibility is low manually, so this method is suitable for roasting machines that control the rotation speed of the exhaust motor with an inverter (installed in electronic devices that change the frequency, such as Giessen and Meister). I will explain the basics.
Roasting is similar to sailing a sailing ship such as a yacht, planning the time and speed in advance, measuring, manually adjusting the error with the plan continuously, and finally checking it with your eyes instead of using a gauge. to reach the destination.
Next, I will explain the general flow of roasting. The diagram below shows the roasting machine.Thermometer shows onimportant to the temperature rise curve ofbean temperatureThis is a conceptual diagram in which .
When the roaster reaches the pre-determined input temperature, the beans are added.1 seam, 2 seamsbe judged on the basis of
When the cell wall constituents weakened by heating due to the increased steam and gas pressure from the beans burst, cracks occur a total of two times. Pichi Pichi, the hot air type will make a popping sound, but not all the beans will sound one by one.
The definition of cracks varies from person to person, but in this article, we define cracks as the first crack that pops.
Also, the most important thing to note isthermometer temperatureonly shows the temperature of the metal part at the tip, sobean temperature(How to measure the bean temperature will be explained later.)
When raw beans are addedthermometer display temperatureThisMinimum temperature (midpoint, Turning point)Back and forthbean temperatureAt 100°C, the water boils and absorbs the heat of vaporization, so the increase inthermometer temperaturebecomes harder to rise,
Also, the time it takes to reach the lowest temperature and the speed at which the thermometer rises in the first few minutes will vary depending on the model, individual differences, installation environment, and amount of input. Plan in advance the time to finish roasting, the amount of exhaust, and the desired finish of the beans.
Gradually, a chemical reaction called the Maillard reaction begins, and at 130°C, the water inside the beans boils, and at around 150°C, the polysaccharides hydrolyze and the Maillard reaction becomes stronger. Hemicellulose in the cell wall begins to thermally decompose,
When lignin melts, 1 crack occurs at exactly 200°C, and cellulose thermally decomposes to cause 2 cracks at exactly 220°C.(In this book, roasting after 220°C, where two cracks occur, is called dark roasting.)
After one crack, the beans are puffed up to the target degree of roasting without wrinkles for a few minutes. This time period is called development phase or development time in English, and the rate of temperature rise during these few minutes greatly affects the taste of the beans.
Before dark roasting, the normal roasting time is before 2 cracks, and the right time is determined by looking at the beans with a test spoon (bean spoon). 7 to 10 minutes from the lowest temperature for 1 crack, and 2 to 5 minutes after that. This is the standard roasting time for a small roaster when the wind power is not adjusted halfway through the roasting process.In the case of roasting with the wind power adjusted, the wind power is reduced in the first half, so it takes longer than 20 minutes. It often happens.
3 Progress of roasting
up to 2 seams below"Temperature of beans themselves"We have listed the chemical changes that accompany an increase in , provided that these temperatures arebean temperatureis"Thermometer Display"just shows the temperature at the tip of the thermometer, soThere is always a difference from the actual bean temperaturePlease note that, for operation, domestic semi-hot air type is in mind,
This is my hypothesis based on measurements using an infrared radiation thermometer, which will be described later, but regardless of the shape, size, or hardness of the beans, one crack occurs in all varieties, and one crack occurs because a substance called lignin melts at 200°C. It is thought that this happens when the gas generated by the chemical reaction becomes unable to withstand the increased pressure, and this is the same as popcorn, regardless of its shape and size, exploding at 180°C due to the thermal decomposition of hemicellulose.
・７０℃that's all
Contains chlorogenic acid (slightly astringent), a type of polyphenolHydrolysisstarts slowlyExcessive caffeic acid (quite astringent taste), quinic acid (sour taste), ferulic acid, etc., which are the source of "sour taste", begin to be generated.
Various chemical reactions beginStarts an endothermic reaction (a phenomenon that takes away heat such as the heat of vaporization of water).
・100ー100
where near the surfacefree water(moisture bound to other components in the moleculebound waterOn the contrary, free water is water that easily evaporates and is also used by microorganisms). From here, polysaccharides such as sucroseHydrolysisare converted into sugars such as glucose and fructose,
Occurs when heated with amino acidsMaillard reaction(Chemical reactions that create various aromas and richness that occur when sugar and amino acids are heated, occur even at room temperature, but occur rapidly at high temperatures to create the aroma and richness of soy sauce, sukiyaki, etc.) began in earnest, and fructose also began to caramelize. increase
・１３０℃
Beans are said to have a temperature difference of 30°C between the outside and the inside, and the moisture inside the beans begins to boil over 100°C. A grassy smell like this comes out, and the beans become whitish, soft and swell.
The reason why it turns white is that the water vapor coming out of the gelatinized starch turns into fine bubbles and reflects the light, just like popcorn looks white. by thermal decomposition or evaporation of waterSince the endothermic reaction is strong, increase the heat depending on the case.Afterwards, the beans temporarily shrink, presumably as the free water evaporates.
・150ー160
In particular, the melting and thermal decomposition of sucrose and glucose (glucose) generated from the hydrolysis of sucrose (sucrose) and starch under acidic conditions at 150 ° C to 155 ° C, dehydration, etc.An endothermic reaction occurs and the temperature rises slowly、Please adjust the heat if necessary.At 160°C, sucrose and glucosecaramelization(a chemical reaction where sugar is decomposed by heat, oxidized and polymerized, loses sweetness, and produces acid and bitterness)
If you stay in this temperature range for a long time, the decomposition of sugar and caramelization will affect the taste, so increase the heat. Starch is probably degraded to glucose via dextrin and maltose (maltose). In beans, rapid simultaneous progress of caramelization of monosaccharides and Maillard reaction begins, and the color of dextrin and caramelization probably cause yellowing and browning. Melanoidin is produced, and the side reaction, Strecker decomposition, produces pyrazine (a fragrant aroma like barley tea or burnt soy sauce), and the beans begin to swell again.
Overseas, many people place great importance on the drying of the beans and judge the progress based on the color and smell of the beans.
・1700ー1800
From 170℃sucrose begins to caramelizemore brown(Sucrose = sucrose does not cause the Maillard reaction.) At 180°C, the hemicellulose in the cell wall begins to thermally decompose, releasing bound water and increasing the pressure.
The chlorogenic acid itself also turns brown and becomes colored while the pressure increases due to various chemical reactions. As the temperature rise slows down, increase the heat if necessary.、
After 180°C, the Maillard reaction and its side reaction, Strecker decomposition, produce a sweet aroma similar to soy sauce and sukiyaki.
・200℃ (1 seam)
The lignin of the cell wall melts the shell-like part on the outside of the beansIt can no longer withstand the pressure of water vapor and carbon dioxide generated by thermal decomposition of hemicellulose,
One crack occurs at exactly 200°C, which is exactly the same principle as popcorn.(Corn for popcorn can be popped at a critical temperature of 180°C regardless of its size and hardness, and ginkgo nuts, soybeans, chestnuts, and popped pops can all be popped at 180°C.
This is because hemicellulose, which is thermally decomposed at 180°C, is the weakest chain ring in the cell wall of plants, but coffee roasted with hot air is very dry and cannot obtain sufficient steam pressure, so lignin must be melted. , This is the same as wood bending at 180°C and 200°C in bending wood).
In this book, when the first grain snaps, it is called 1 crack.Intense dehydration condensation occurs during the first crack, and the heat of vaporization slows down the temperature rise for a while, so adjust the heat before the first crack.It takes about 2 to 5 minutes from the start of the 1st seam to the 2nd seam to expand the beans as much as possible.This is called the development phase.
Furanones such as furaneol (the source of strawberry and pineapple aroma) are also produced by the intense Maillard reaction.Thermal decomposition of hemicellulose also produces a large amount of a substance called furfural, and a strong smell like freshly baked toast, roasted chestnut skin, and kraft paper comes out.However, furfural itself boils at about 162°C, so when the roasting is finished at just before 220°C, this scent is almost gone. When it smells like buns, it's time to move on to the next stage.In other words, no matter how delicious it may smell, there is still a step ahead for beans with a strong toasted or sukiyaki smell.And at this stage there are still extra ingredients that are the source of the "sour and astringent taste".
(By the way, there is also a theory that one crack occurs at 180°C. As far as I know, Carl Staub of the United States published the article Basic Chemical Reactions Occurring in the Roasting Process in 1995, which describes the decomposition and caramelization of cellulose. The first theory is that 1 crack occurs at 180 degrees Celsius = 356 degrees Fahrenheit as the starting cause. If you measure the temperature with an infrared radiation thermometer at the first crack, it will be around 180℃, which is different from the time of the roasting machine. It is caused by the pressure difference due to the difference between the environment and the roasting environment.)
・Before 220℃ (end of roasting)
The timing of the end of roasting is before 220°C, as it will have 2 cracks.The end of roasting is decided by frequently looking at the rapidly changing beans with a test spoon and sometimes using the sense of smell.The taste changes completely depending on how many minutes the beans are left to rise after 1 crack and what temperature they are cooked at.。
When the beans swell, a rapid Maillard reaction occurs and the alcohols (not ethanol, but those with a higher boiling point) contained in the essential oils of the raw beans are converted into carboxylic acids.esterificationEsters, which are the source of the aroma, are produced as a result, and typical examples include 3-mercapto-3-methylbutyl formate, which is the source of the cassis scent.
(It is a mystery why the sudden reaction occurs when the beans swell in the temperature range of 210-220°C. It may simply be the optimum temperature range, but when the beans swell with oil seeping out from the cells, I am dreaming that the carbonized porous structure of is like a catalyst)
As a working hypothetical concept or a kind of ideal typeBeans have two vertices before two cracks, and roasting other than dark roasting ends in the middle time zone.First of all, the sweet scent like sukiyaki fades and gradually changes to a fruity scent, and at the same time the beans swell.Bright and glossy like a child's skinThe place where this fruity scent that even feels sour is the strongest is"Peak of fragrance"Then, visually observe the beans with a sample spoon and smell them to confirm that they have arrived."The peak of richness"Proceed to
Just before the second seam, which is the peak of richness, smoke comes out of the beans, very fine wrinkles disappear, the beans become smooth like a baby's skin, the color is dark, and the surface of the beans is dark.A light oil floats and shines,It looks plump and delicious, and the taste is full-bodied.At this stage, components such as quinic acid, caffeic acid, and chlorogenic acids are finally either completely esterified or lactonized (typically, chlorogenic acid lactone, which is the source of coffee-like bitterness), or decomposed, so it is “sour” or “astringent”. The taste is almost gone, and the smell of toast and sukiyaki completely changes to a coffee-like scent.
If roasted properly, if it is roasted close to the peak of its richness, even if it is two fingers, if you smash it with two fingers, the beans will fall apart and shatter to the inside. Also, undercooked or lightly roasted beans become so hard that they can't be cracked with your fingers about 2 hours after roasting. If you store normal beans as a sample, they will harden in about two years, but high-quality beans will still smell good even after several years.
When the beans are in a state where each cell is hollow and swelled, it can be crushed crisply when brewing coffee.The extraction efficiency is also good, and even the rim of the cup becomes black.。
By the way, the intensity of the color is determined by the amount of melanoidin produced by the Maillard reaction, but there is only a certain correlation with taste and aroma, and the color is only a rough indicator. Please note that there may be a "sour and astringent taste" left.
There are various indicators, and it sounds difficult, but if you roast until dark and take a sample with a spoon at each stage, you can find the optimal roasting timing for each bean.
・220℃
Two cracks occur at 220°C.In this book, if even one grain pops and rings, it is defined as having entered two cracks, and after this is called deep roasting.It is a hypothesis, but this is probably also the thermal decomposition of cellulose at 220°C. Beans make a little noise due to the pressure from dehydration condensation, etc.
It is thought that the brittle beans can no longer withstand the increased pressure, and the inside of the beans swells, causing 2 cracks. If the water content at this stage is low, the sound will be low) 2 Around the crackvanillin from ligninbegins to be produced, and a sweet aroma peculiar to dark roast begins to appear. make the taste of
I don't know whyThe fruit-like scent disappears in an instant when it enters the second seam.
This is probably accompanied by oily smoke from the carbonized holes on the surface at the boundary of the 2nd seam.oil seeps to the surfaceThis is probably because the fragrant ingredients become hot in the oil and disappear.
Also, if the beans get 2 cracks even for a moment, even if you stop roasting before the oil comes out, the oil will seep out like sweat after a few days. It sticks, but beans before 2 cracks will not stick no matter how oily they are, so you can easily tell them apart.
・Over 220℃
As will be described later, with the Japanese single drum roaster, it is better to roast the beans a little longer than to finish roasting immediately after the second crack, resulting in a sweeter coffee with a stronger vanilla aroma.After 2 cracks, the temperature rises at an accelerated rate due to the exothermic reaction, and the thermometer becomes unreliable.
There may be some beans that have a better flavor if they are roasted slightly past 220°C.For large beans, if you finish roasting a little past 2 cracks, the astringent and sourness will not be completely removed, so we recommend roasting large beans for 2 cracks plus a deep roast of about 30 seconds., Vinyl catechol oligomers, which are the source of bitterness, are also strongly present, but some bitterness lovers prefer it, and it has a stronger vanilla scent, which is the sweetness of dark roast.Be careful, as dark roasting can cause fires.
In addition, deep roasting, which causes oil to spurt out during roasting, probably requires time for the smoky surface to hydrolyze before it is ready to drink, and the carbon dioxide packed in the porous structure wraps the beans. Both the melanoidin and the oil on the surface have strong antioxidant properties, so it takes at least a week of aging to reach a level of oxidation that produces a pleasant aroma like wine. About 20% weight is reduced from raw beans.
・230℃ (3 seams)
Lignin begins to thermally decompose at 230°C, and the slight pressure of the dehydration condensation can produce a slight sound depending on the conditions of the roaster and beans.
At this point, the surface is carbonized and looks like boiled black soybeans, and it takes more than 3 weeks to ripen.
When the oil blows up to this point, the oil itself has oxidation heat and the temperature rises rapidly, so be careful not to ignite it. Also, be careful of igniting chaff and sticky oil stains inside the roaster.
Be really careful with fire.
4 Example of roasting practice ~In the case of domestic semi-hot air roasting machine~
First of all, before we start roasting for the day, we consider the roasting method, order, and amount of roasting according to the difficulty of roasting for each category. The timing passes in an instant, and the number of times the gas pressure is adjusted is large. For example, first deep-fry small beans (or do the first half of double roasting described later)
After that, roast the beans that are easy to roast several times, starting with the beans that are roasted in the smallest quantity, and roast the beans that are difficult to roast after the roaster has accumulated enough heat.
1st round: dark roasting of small beans 2nd round: dark roasting of large beans 3rd round: normal roasting 4th round: light roasting
If you get used to adjusting the heat power or have enough room in the roasting machine capacity, you don't have to worry about the order so much, but the first few times of the day the preheating is insufficient and you need to calculate and adjust the heat power. is.
There are 100 different types of roasting, but the following is a Japanese drum-type semi-hot air roaster that uses a single fan for exhaust and cooling.One caseI will explain the hot air method later.
０Set the daily roasting amount, order, and input temperature (generally 150-180°C for semi-hot air type, around 200°C for hot-air type)
１For the first time, close the damper and preheat the roaster until the thermometer reaches 200℃. 2xx ℃ exhaust thermometer 2xx ℃, etc.) increases the reproducibility of roasting.
２Lower the heat or extinguish the heat to slowly lower the temperature, then add the beans for the first time.
３When the temperature displayed on the thermometer drops and hits the bottom, open the damper or increase the heat.The time required to reach the lowest temperature varies depending on the model.
４Adjust the gas pressure so that the temperature rises to 1 crack in about 7 to 10 minutes from the lowest temperature as a guide. If the beans have a particularly high moisture content, increase the time until cracking occurs. , 150°C, 170°C, 180°C and 200°C, increase the heat when the first crack starts, if damper is used, adjust any time from 150°C to 200°C.
５When one crackling sound occurs continuously (or after x seconds have passed since the first cracking), reduce the gas pressure and let the beans rise for about 3 to 4 minutes. to confirm.
６Bake, or add 2 haze to dark roast, then close the damper, open the lid, transfer the beans to the cooling tank, stir, flatten evenly so that the punch holes in the cooler are not visible, and cool. If you can see the punch holes between the beans when the stirrer rotates during roasting, the cooling efficiency will decrease, so you can stop the stirrer when the beans are flattened. At this time, if the roaster has a separate exhaust system, you can roast continuously (in parallel with cooling).
７When the roaster reaches the input temperature, put the beans in and start the next roast.
８When the roasting is complete, run the motor and let it cool to about 50-60°C, then turn off the power.
5 Difference between thermometer and bean temperature
The thermometer on the main body of the roasting machine indicates that when the beans are at a temperature of 130°C, the moisture inside the beans boils, causing the beans to grow larger and then the moisture to escape, causing the beans to shrink and wrinkle, as well as gas generated by various chemical reactions. And the steam of dehydration condensation will swell again.Every time the size of the beans changes, the way the beans and the hot air hit the beans changes, and the thermometer does not match the temperature of the beans.
1 crack at 200°C, 2 cracks at 220°C, this is the same for any kind of beans, but the temperature of the thermometer rarely shows exactly 200°C at 1 crack (for example, Fuji Royal's 1 crack is 170°). From c to 180°C in Giessen, 1 seam 196°c 2 seams 224°c) This is probably due to the effect of hot air if the display is higher than the bean temperature, and if the seam temperature is extremely lower than 200°c, it is probably half In the hot-air method, the heat conducted from the drum causes some beans to crack before the thermometer reaches 200°C.
In other words, the thermometer on the main unit is affected by three factors: displacement, heat storage, and bean size.
In this way, the temperature of the thermometer differs from the temperature of the beans due to various factors, but if you record the important temperature, you will be able to achieve stable roasting every time.
Three temperatures are particularly important.
① 150℃ at the end of draining
Draining endIn other words, a temperature of 150°C to 155°C is an important point in determining the time allocation, because if the moisture is not removed by then, the hydrolysis of the polysaccharides will progress too much or the cooking, which will be described later, will occur too much, resulting in an odor.There is no clear indicator like the crackle sound, but there are some indicators that can be used as a reference.
First, the thermometer becomes difficult to rise, the color becomes darker, the beans swell a little, and the smell changes to caramel, and a lot of smoke comes out.Infrared thermometerto measure the amplitude with the main body thermometer,
Of course, there is always an error, but it is sufficient as a guideline.
②200℃ 1 seam
With a semi-hot air fan made in Japan, one crack may occur in the 170°C range, but before the thermometer reaches 200°C, one crack occurs at a distance from the thermometer (probably strongly influenced by the conductive heat of the drum). Since the temperature is just 200°C, there is no change in the fact that one crack occurs, and the thermometer is a thermocouple thermometer probeIt just shows the temperature of the tipOn the other hand, for example, with a hot air system, the temperature may be displayed several degrees higher, such as 203°C on the thermometer at one crack.
③220℃ 2 seams
The difference between the bean temperature and the thermometer after 2 cracks is thought to occur because the beans swell after 1 crack and the way the beans hit the thermometer changes.
With a single drum roaster that uses a lot of conductive heat, if preheating is sufficient, the difference between the temperature on the thermometer and the bean temperature at the second crack will stabilize at a constant value.Until then, the thermometer display at the time of 2 cracks may be slightly different every time, but if you measure with an infrared radiation thermometer, you can predict the approach of 2 cracks.
Also, the warmer the air, the more it expands, making it harder to blow air, and even if the air pressure is low, it expands the same way. There may be differences due to weather conditions, etc.
6 Data collection and profile creation
"What is important for reproducibility of taste isIt is to reach the bean temperature 150℃, 220℃, 220℃ in the same time every time after reaching the lowest temperature.Therefore, accurate bean temperature and data of the difference between the thermometer is required. Check the bean temperature with a heat-resistant pen typeInfrared thermometera sample spoon of beans as soon as possiblezero distance(There is no need to completely remove the spoon.) You can buy this type of thermometer online for several thousand yen. It cannot be said to be perfect because it is affected by gas and water vapor.Always a few degrees of errorthere is a realIt will be a guideline for the bean temperature.
The model is A&D Radiation Thermometer AD-5617MT
When starting to use a new roaster, first determine the exhaust volume for the type and amount of input, and then decide how long it will take to complete the roasting. record.
・The weather, room temperature, and the temperature and condition of raw beans
・The input temperature and the number of times of roasting at that time
・The lowest temperature on the thermometer display and the bean temperature at that time
・ Thermometer display when bean temperature is 100℃
・The bean temperature is 130℃ and the thermometer display at that time.
・The bean temperature is 150℃ and the thermometer display at that time.
・The bean temperature is 170℃ and the thermometer display at that time.
・The bean temperature is 180℃ and the thermometer display at that time.
・When the bean temperature and the temperature on the thermometer start to separate
・The number of times of continuous roasting and the bean temperature and temperature display for 1 and 2 cracks
・Time between 1st crack and 2nd crack
・Recording the taste over time for about 10 days from immediately after roasting
And so on.
First, the thermometer records x°C at these bean temperature x°C points, then records xg of green beans rising by x degrees in x minutes, and so on. Explore wind power.
By the way, Japanese city gas is 13A and 1KPa to 2.5KPa, propane gas is 2KPa to 3.3KPa, and the calorie is 2.23 times that of city gas. Please be careful when referring to the profiles of other stores as they have been adjusted to be the same with the number of sheets etc.
In addition, the temperature, room temperature, humidity and pressure of the day also affect the air volume and volume, which affects the exhaust volume (especially if there is a chimney, it is also affected by the back flow to the chimney), so the weather and temperature should be recorded. Let's keep
Check the taste with a paper filter for home use.
In particular, (1) if you drink it after it has cooled down, you will be able to clearly understand the miscellaneous tastes that occur due to hydrolysis in the cup when the reaction is insufficient. If so, then there is no doubt that the roasting for the Japanese market was a success. Furthermore, ③ if the dried beans remaining in the filter smell good even after standing overnight, it is a great success.
7 Features of the hot air roasting machine
Now let's move on to the explanation of the drum-type hot-air roaster.I will increase the gas pressure.
A double-drum roaster such as Probat, which has double drums and is insulated, has high heating power from the lowest temperature to around 130°C (or immediately from the time of insertion) when the thermometer shows that it is loaded at around 180°C to 200°C. is required,
After that, little by little with the progress of roastingLet the gas pressure go down,At critical temperatures, e.g. bean temperatures of 150°C and 200°C,The roasting can be done by 'holding' the gas pressure for a short period of time and then reducing the gas pressure again after reaching the target temperature rise, or increasing the gas pressure slightly at a critical temperature and then decreasing it again. For this reason, there may be some inconsistencies between Japanese literature and overseas literature.
Hot air profiles vary considerably from country to country, but from what I've researched, it's roughly 15 minutes or less per roast, and the time allocation is:
Charged at Charge Temperature (minimum temperature is Turning Point) From charge to Dry end or Gold Point around 150℃ is called Drying phase, 30% or more and 50-60% or less of the whole (according to Giesen 6 to 8 minutes after input)
The Maillard Phase from dry end to 1 crack was about 40% or less of the total roasting process, and the Development Phase from 1 crack to end of roast was less than 30% of the total.
Also, overseas, the rate of rise in temperature per minute (ROR, Rate of Rise) and the Development Time Ratio (DTR, the percentage of the total time from the first crack to the end of roasting) are often used as indicators.
I'll explain why laterThe taste varies considerably depending on the roasterFor dark roasting, the single layer and half hot air method gives a richer and sweeter taste. Perhaps this is the reason why Japanese people have long preferred large mandheling and Guatemalan beans. This is because when roasting large beans, the characteristic richness of semi-hot air stands out.
Also, in Europe and the United States, the roasting time became shorter with the spread of double hot air roasters after the war (roasting time took 30 minutes for one roast with a gas shop roaster in Europe before the war, and in Japan it was several decades ago. Until then, it was not uncommon to roast for 30 minutes per roast).This is probably because the hot-air double-drum method can no longer produce sweet, deep-fried roasts like the single-drum half-hot-air method.
(By the way, Starbucks is very rare for an American company. Even today, they use a super-large fluidized-bed roasting machine to roast 2 grains in just 3 minutes. It is said that they put it in the goby and made it dark-roasted in the Dutch style before the war.
On the other hand, the hot air type2 The scent in front of the seams is well emitted, I used the hot-air roasting, a favorite of the Germans, to reach the peak of aroma.We call it German roasting.(In the German-speaking world, due to the influence of the United States, there are many medium roasts in the American style, where the bean temperature is about 210°C.)coffee beansPlease do an image search in German, but it's still a little sour for Japanese people.
After this stage, hot air roasting takes about 3 minutes after the first crack to 220°C until the acidity is almost gone.Italian style roast(There is a tendency for roasting to be a little shallow in areas such as the northern part of the country influenced by the former Austrian Empire). Although the espresso beans are dark in color,Before 2 cracksto the extent that it is shinyfull-bodied beansis the mainstream,Coffee beansand do an image search in Italian,
In southern Italy we roast even darker, but even Robusta is not double cracked,Austrian roastCurrently, it is mainly for espresso, and it is a dark and glossy roast that is deeper than Germany and shallower than Italian style before 2 cracks and acidity.
8 Exhaust adjustment
The valve that adjusts the exhaust is called a damper. Basically, the damper operates only when the roaster is preheated, when the beans are cooled, and when the amount of beans input is changed. Basically, it is during roasting. There is also a special roasting method that changes the wind power with dampers and inverters.
If the exhaust is too strong, the room temperature air will be drawn in, resulting in a lack of calories. There is also a method called neutral roasting, which is recommended by Fuji Royal by adjusting the exhaust volume of the roaster and transferring the heat well.In this method, when the temperature rises, the air expands and the exhaust efficiency decreases, so it is better to gradually open the damper and adjust it. However, it is very difficult and requires experience to manually operate and optimize the displacement of the roaster.
For example, in the Dietrich roasting machine developed by Mr. Stefan Dietrich, an aircraft engine expert, the damper is operated only during cooling and warm-up operations (the same single drum as the domestic machine, and the cooling fan and exhaust fan are shared, but the carbon steel drum structure is quite different)
If you want to change the air volume in detail, it is recommended to use a roaster with an inverter, which is common in large machines.
As far as I have researched, it seems that the origin of the damper attached to the small roaster in Japan comes from the Royal roaster, which was popular in Japan and the Americas before the war. The direct-fired roasting machine (the direct-fired roaster itself originated in England) had a structure in which a single motor was used to rotate the drum and rotate the exhaust fan.
According to the book of the late Mr. Ichiro Sekiguchi, famous for creating flavor by manipulating the damper, in Japan, American-made roasting machines such as Burnsroasters (founded by Mr. Burns, the father of modern roasting, and still under the umbrella of PROBAT) Making a large punching drum type roasting machine, a rare format different from direct fire ⇩ YouTube video)
BURNS B270R Feature (Imperial) | BURNS Industrial Coffee Roasters and Coffee Processing Systems - YouTube
I was using European-style dark roasting (French roasting like in Holland and France, roasting low-quality Robusta beans in colonies in the original sense until the oil is thick), but it feels strange It seems that the old-fashioned Japanese roasting called direct fire roasting had already started at that time.
From pre-war to post-war times, the so-called “butagama” of the old Fuji Machine and Lucky Coffee Machines, which were strongly influenced by American-made roasting machines, appeared and became popular along with home roasters.
At that time, the single-drum semi-hot air type with independent exhaust fan motor became popular in Japan, and the double-drum hot air type became popular overseas. So there are some manufacturers of single drum roasters that are descended from the old roasters.
Interestingly, the San Franciscan Roaster roaster touts its ability to control both conductive and convective heat, using manual dampers and inverters to vary drum rotation and wind force during roasting.
https://perfectdailygrind.com/2019/02/coffee-roasting-guide-what-is-airflow-how-can-you-control-it/
This is the same as the design concept of Yamato Iron Works Meister equipped with an inverter that Mr. Taguchi of Cafe Bach was involved in designing Fuji Royal, which Mr. Sekiguchi used regularly. It is like a convergent evolution, and it is the same until the air volume is reduced in the first half of the drying stage. It seems that there is a technique aimed at the same effect as steaming.
https://millcityroasters.com/commercial-coffee-roaster-news/what-is-a-soak
In addition, there are many manufacturers in South Korea, Taiwan, and China that have been influenced by Fuji Royal, so the roasting method described below using a Japanese damper is spreading overseas.
On the other hand, German-made Probat dampers (Currently, there is no rotary damper in the small Plot machines, but some medium-sized roasters such as the UG series that have been around for decades have an aroma wheel. Even if it is in a small roaster, it seems that it is usually fixed, and it seems that it is designed with the aim of roasting beans at least half of the capacity and roasting them efficiently with hot air to make them fluffy and fragrant.
Illustrated domestically produced single-drum semi-hot air system
9 Various roasting methods
In addition to standard roasting, there are various roasting methods such as:
①Conductive heat enhanced roasting
This is a general term I gave to roasting that changes the taste of beans by operating the damper or exhaust fan mentioned above. This includes reducing the number of rotations of the cylinder).The ratio of convective heat and conductive heat that gives heat to the beans is higher than conductive heat."Drain"is called
In fact, weakening the wind force is like stopping the blowing of a convection oven, so on the contraryThe ratio of convective heat should be low and the beans should be less likely to dry. It has a strong sweetness and richness. This is thought to be due to the fact that starch is hydrolyzed to increase the amount of monosaccharides, which in turn causes the Maillard reaction to occur more strongly, resulting in a stronger richness.(The Maillard reaction is said to occur easily at a temperature of about 155°C, a water content of 10-15%, and a water activity of about 0.6-0.8.)
this operation"Steam"Some people call it that, but this is probably a name that emphasizes that heat is transmitted firmly to the inside of the beans using moisture as a medium by suppressing evaporation.
As a result, the temperature rise becomes weakerlonger roasting time,Cooking, which will be described later, will take longer to soften the beans, and the moisture will eventually evaporate.
However, if this method fails, the moisture will not be completely removed, and the dehydration and condensation of the ingredients will be insufficient, resulting in no fragrance, and conversely, hydrolysis will tend to produce an unpleasant sour taste, so it may be better to use it for deep roasting. In my opinion, this kind of roasting that changes the amount of exhaust air during roasting reduces the unevenness of roasting beans even a little, Isn't it a roasting method that was born as a result of the effort to make it sweet again?
Of course, in addition to dark roasting, it may be effective for beans with less moisture such as natural or honey, butIf the bean temperature stays too close to 130°C, 150-155°C, and 170°C,Excessive hydrolysis may cause too much oligosaccharides, resulting in the Maillard reaction or excessive caramelization, which may result in a sweet aftertaste or adverse effects, so please be careful. It is also used for roasting (roasting such as Café Bach, which uses a domestic semi-hot air machine to raise the temperature from the lowest temperature to the first crack by a thermometer, which increases an average of 5-6 degrees Celsius per minute).
In fact, I haven't written about it in detail to avoid confusion, but the seam temperature sometimes differs with the single drum domestically produced semi-hot air roaster.
In modern roasting machines, the beans get 1 crack at exactly 200°C. In this combination, the evaporation of water is delayed, so the pressure is kept strong, and in rare cases, the first crack may occur at 180 ° C, where hemicellulose thermal decomposition occurs.In this case, the second crack starts at 200 ° C., 180°C is considered to be 1 cracking in the literature, so it is considered that the same phenomenon occurs because the moisture does not easily evaporate because the oven is used for experiments. .
There is a difference of exactly 20°C, so it's confusing, but basically, whether it's made in Japan or overseas, it's unlikely that modern roasters will crack at 180°C unless you do extreme operations. I have only experienced it when I made a mistake in the operation.
Also, if the roasting is too long and it is too dry, it may not be at 220°C, but at 230°C, where lignin is thermally decomposed, to crack 2 for the opposite reason.
②Double roast
Double roasting is a method in which beans that are difficult to roast due to their high water content are dried until they turn from whitish to pale yellow, or until they reach nearly one crack. If you don't completely cool and harden the beans, the water will evaporate too much, and double roasting will inevitably weaken the aroma.
③ Mixed roasting
It is a roasting that mixes several types of beans from the beginning, and inevitably there will be unevenness in the roasting of each type at the end of roasting, so it is mainly used for extremely dark roasting so that the oil spreads all over.
④ Water polishing and roasting
Water-grinding roasting is a roasting method in which water is used to rub the beans together to remove the thin skin (chaff), etc., and to "sharpen" the beans.
If you "soak" the raw beans, excess moisture will seep in. Use a colander to quickly finish the roasting within 60 seconds and remove the moisture before it soaks in the water before starting roasting or using a fan to dry it.
However, no matter how quickly the beans are dried, once they absorb moisture, they tend to leave water behind.
・Astringent and sour scent
In the early stages of roasting, it takes a long time for chlorogenic acids to hydrolyze, making quinic acid caffeic acid too sour.In addition, esterification and lactonization due to dehydration condensation of chlorogenic acids and quinic acid do not occur sufficiently, and the ingredients remain as they are. Since it remains, the chlorogenic acid itself does not have a scent, and the astringency of the chlorogenic acid itself remains.It has an astringent taste that makes the tongue shrink like eggplant and burdock lye. it's like drinkingunder abdominal painwill be
・No richness
It lacks richness and tastes flat. This is probably because the Maillard reaction does not easily occur if the water content is too high or too low (optimal range is 10-15% water content and water activity 0.6-0.8). It's like adding a splash of water when roasting or frying spices.
・easily painful
Chlorogenic acid and a small amount of furanones and lactones that remain in the beans will eventually hydrolyze, and the astringent and sour aroma will fade, and the shelf life will be short even at room temperature. In other words, if the beans are roasted while absorbing water, they may look good, but the taste and aroma will be faint, and the beans will go bad quickly. If you wash it with water, the taste will be thin and the flavor will be lost." This is because it becomes beans that have absorbed moisture to the inside.
The thin skin is sterilized with hot air during roasting, and finally the thin skin on the surface is peeled off like the thin skin of a ginkgo tree or the skin of a mandarin orange.
In the first place, tea and black tea are not washed with water during the refining process, nor are they ground with water when roasting spices or hojicha. Even coffee beans in countries such as Germany, Austria, and Italy do not wash their beans when roasting. On the contrary, we pay attention to adjusting the moisture content from the refining and distribution stages.
I know that the coffee ceremony in Ethiopia is washed with water, but that is not a roaster, but a charcoal fire and an iron plate, and the premise is to roast the wonderfully fresh beans that are not available in Japan in a hand pan and slowly stew them. It's a culture, of course, there are delicious shops that use a roasting machine and roast with water under Japanese conditions, but after washing with carbonated water or special air bubbles, it is double-roasted and the oil goes around the whole. It seems to be roasting, but if you want to grind it with water, you need to make it super dark roast without sparing that much time and effort.
10 Roasting failures and countermeasures
In most cases, roasting failures that are clearly unsatisfactory are caused by an imbalance between the amount of beans and the exhaust and heat power. .
(1) Excessive heat conduction
If the heat is too strong for the amount of beans and the exhaust (especially in the first half of roasting), the beans will be heated only by conductive heat and moisture will remain, and the excessive melanoidin produced from sugars produced by hydrolysis such as starch will produce a flat sweetness. The sourness and bitterness of caramel and caramel will appear, and the individuality of the scent will disappear.
② Excessive exhaust
The exhaust is too strong for the amount of beans and heat power, and too much room temperature air is taken in and not heated enough.Smell is faint and astringentIt tends to be, especially when roasting with a roaster with little heat storage or when the heat is squeezed too much.
③ Excessive heating
Even if the heat and exhaust are well balanced, the amount of beans is excessive = the temperature rises too quicklyThe inside of the beans is undercooked and has an odor, and only the surface is roasted.This is especially noticeable with a fluidized bed hot air roaster that takes only a few minutes to finish roasting green beans.
If the beans are soft and juicy, lower the throwing temperature. If the surface has mottled scorching, the throwing temperature is too high or the initial heat is too strong, so adjust it a little.
In addition, if the surface temperature rises too fast without adequate time for stretching after the first crack, the water will not be completely removed, causing a violent hydrolysis reaction, and excessive acid will be generated and left behind. teethbitter and sour tasteEven if the appearance is beautifully baked, even if there is only a small amount of remaining moisture, the delicious ingredients will be hydrolyzed immediately. As this progresses, a bitter, cheap red wine-like harshness and bad aftertaste, which is thought to be derived from chlorogenic acid, may stand out.
④ Insufficient heating
If the heating is insufficient, the components produced by excessive hydrolysis will not be esterified and lactonized, and will remain as they are, resulting in a so-called "drainage failure" state, which is caused by hydrolysis in the same way as excessive exhaust.bitternessEspecially, if the moisture cannot be completely removed and the beans are put into the second seam, the pressure of the beans becomes too high, and a part of the brittle skin is blown off (so-called chipping, crater) at the time of the seam. because it didn't happenDiminished taste and aromaincrease,
In particular, if the amount of water is not kept in the appropriate amount during the drying stage up to 150°C, a fishy odor comes out in the stomach.
Furthermore, the roasting time is unnecessarily long.It has a bad aftertaste and is sticky, like burnt brown sugar, and leaves an unpleasant sweetness.This is probably due to too much hydrolysis of the polysaccharides with accompanying caramelization and too much Maillard reaction, and also because the bean surface isA tingling taste or smoky odorin some cases
(Smoky whiskey, stinging like vanilla extract, underdried smoky taste, maybe phenols?)
In these cases, the input temperature is too low, the amount of heat in the first half is too small, orwater remainsBecause of this, it has become a kind of so-called off-flavour, especially in natural manufacturing methods.Smell like stuffy sweatbut alsoIf the heat in the first half is insufficient, it cannot be recovered even if it is heated strongly in the second half.It is important to give the beans an appropriate amount of heat by bringing them to the first crack with sufficient heat or slowly cooking them for an appropriate amount of time.
The important thing is to determine the appropriate amount of beans to be loaded for the capacity of the roaster, then set the appropriate exhaust volume according to it, and finally adjust the heating power to achieve a well-balanced and appropriate temperature rise. is that
If the taste is still bad, the beans may be of poor quality or poor storage conditions.
11 About raw beans
・Simple classification of beans
The beans were simply classified based on various bean classification methods.
It is an easy-to-remember classification that focuses only on the ease of roasting and the amount of moisture, omitting thickness, density, etc. Please understand that there are many exceptions.
moisturemanystomach
moisturefewdo not have
roastingeasy
·small
·thin
·soft
Features such as
1.Taraku Group
Ethiopian Washed
Haitian Washed
brazilian washed
Blue mountain
Such
2 Shogaku Group
brazilian natural
ethiopian natural
Yemeni Mocha
Peaberry
Robusta
Such
roastingDisasternew
·big
·thick
·hard
Features such as
3 difficult group
Mandelin SG
ColombiaExcelso Premium
Nicaragua SHB EP
Guatemalan SHB EP
KenyaAA TOP
TanzaniaAAA
Papua New Guinea Sigri AA
Such
4 Slight difficulty group
Colombian Natural
Nicaraguan Natural
Guatemalan Natural
peruvian natural
indian monsoon
big old beans
Such
1 Taraku Group
A strong fruity aroma and a clean, sophisticated taste.
2 Shoraku Group
Many of the coffee beans have a low density or are small, making it difficult for water to remain, making them easy to bake.The chlorogenic acid probably remains without much hydrolysis, and the bitterness peculiar to coffee, which is thought to be due to chlorogenic acid lactones, is strong.
3 Difficult group
The starch and sucrose are strongly hydrolyzed, so there are many sweet ones.
4 Slight difficulty group
Because the hydrolysis of starch and sucrose is difficult to occur and the sugars that are the basis of the Maillard reaction are difficult to produce, caramelization and other aromas are strongly felt.
・Buying beans
We always purchase raw beans directly from trading companies.A long time ago, it seems that individual roasters were not taken into account and they were sold by medium-sized roasting groups, but now that there is the Internet, you can buy directly from small trading companies. The grade of raw beans varies considerably depending on the country, and sometimes trading companies have their own sorting, so let's check directly with the trading company and remember. There are companies that sell smaller batches of 10kg per variety. My criteria for choosing a trading company is Mandelin SG made from new beans (new beans are called New Crop, which are green and have a lot of moisture, and old beans are Past Crop). It is (SUPER GRADE), and I drink the most expensive beans from among the native beans from Ethiopia Irigachev (Ethiopia Yirgachev production is only a famous brand, so it is a mixture of cobblestones)
Once I am satisfied, I will try beans from famous production areas such as Kenya, Guatemala, Colombia, and Brazil, starting with the most expensive ones.Green beans are selected from expensive beans (within the acceptable price range),The price depends on the exchange rate, but as of 2020, high-quality specialty coffee is sold in bags at 1,500 yen per kilogram. The standard price is equivalent to 10 bottles of Coca-Cola.
However, some beans are produced in developed countries with high labor costs, such as the United States, Australia, and Taiwan, and are priced particularly high due to awards, branding, and auctions. If frost damage (agricultural damage caused by a sudden drop in temperature) occurs, the price of everything from Robusta beans to specialty beans will rise, so be careful. The price of specialty coffee entering the country will continue to rise in the long term due to globalization and the decline of the Japanese economy.
・Preservation of raw beans
Raw beans are vulnerable to humidity, light, outside air, high temperature, condensation due to temperature differences, mold, and insect bites. It is said that it is best to store it in a refrigerator, but it is difficult to store it unless it is a refrigerator for brown rice. I think that selling 20 or 30 kinds of beans is too many kinds. Many people store it in a vacuum (deaeration) bag or plastic pail that can be tightly sealed.If you seal it up, it will deteriorate quickly after opening (oil oxidation, etc.), so if possible, use it up within a few days.In the case of a small store, you can use a container such as a rice box with packing, or divide it into plastic rice bags and put an oxygen absorber or disposable warmer in a futon compression bag to degas and store it as it is like a vacuum pack. First of all, it's a good idea to put it in a container with something that absorbs moisture, such as silica gel, to avoid temperature changes and humidity and sunlight.
with old raw beansIf the amount of moisture is below the appropriate amount (generally, 8-12% of green beans is said to be the appropriate amount), the aroma will be stronger than the original characteristic.It may be thin, and it may taste like hojicha (roasted green tea) at best, or dried grass at worst. In addition, it is thought that caramelization is the main flavor because the Maillard reaction does not reach the optimum range due to lack of moisture (conversely, new beans have a lot of moisture and darker color).This is called aging, and humidity and temperature are controlled. There are also stores that store beans in a warm environment for a long period of time (1 to 30 years) to prevent them from getting moldy. I can smell it.
・Sorting beans
There are foreign objects in the beans, elephant beans that cause uneven baking, peaberries (round beans that normally contain two beans instead of one), flat beans that contain two, flat beans) cracked beans, moldy beans that make the taste extremely bad, wormy beans, shell beans (only one of the two beans grew in the fruit), fermented beans, chipped beans, drum preheating There are things called "defective beans" such as tipping, which is burnt at the edges due to unevenness or too fast rotation.
When roasted, the color and shape of the defective beans stand out and are easy to understand. For some reason, the defective beans remain hard even if they are roasted in semi-hot air roasting.。
It takes a lot of labor, so it's better to buy beans of good grade and price that have been sorted locally as much as possible.
However, coffee is an agricultural product like rice, so no matter how good the lot is, it is impossible to eliminate defective beans.
・Smell of beans
Beans originally contain various odorous components, which disappear or increase depending on the roasting. At the stage of reducing the amount, if the amount is reduced too much, the bitterness will become stronger.In overseas countries, the temperature is often between 150℃ and 155℃.dimethyl sulfideThis ingredient gives off an odor that makes the upper jaw and stomach shrink (actually, if you have an upset stomach, the protein in the mucous membrane is decomposed and this substance is produced, so this is likely related). It smells like raw garbage, seaweed pools with algae, rotten green tea, horse manure, and cut grass.
this is probably a beanDistillationCooking is the process of dissolving lignin by pressurizing and heating alkaline agents and auxiliary agents such as quinone when producing paper pulp from wood chips. However, odors such as dimethyl sulfide are generated.
Beans contain minerals such as sulfur and potassium, and coffee is a plant of the Rubiaceae family rich in quinones.
It is believed that this cooking causes the beans to soften temporarily during roasting.
By the way, paper cooking seems to be done at 130°C to 150°C.。
Other odors produced by roasting include acetaldehyde, which has a pungent green smell similar to tobacco, strong butter and cottage cheese, and diacetyl (called in Japanese sake), which is the source of the smell of sweat. These odors remain in the beans after roasting.All of these occur when there is a calorie deficit during roasting, especially when the beans are not drained well in the first half, which is why some people smell the beans to check the progress of draining. .
By the way, mandheling is reddish brown (a brown substance is produced by the reaction of chlorogenic acid and sucrose, and the reaction progresses from yellow to red to black), like cooked brown rice.sulfur smellHowever, the best mandheling is black like black soybeans if it is baked well, and has a faint indigo color (like black soybean dyeing, probably due to the reaction between polyphenols and acid) when ground.Fragrance like Chinese quince and fragrant woodI will.
As an aside, dark green and fishy beans are said to be beans with a lot of moisture, but this is probably because chlorogenic acid is oxidized under basic conditions and reacts with amines to turn green. Udo containing chlorogenic acid, Sweet potatoes and burdock also have greening phenomenon. Washed and Sumatra beans may produce ammonia during fermentation, which may make them basic.
12 Preservation and blending of roasted beans
・Preservation of roasted beans
"How to store roasted beansTemperature, Humidity, and UV RaysHigh temperature accelerates the decomposition of ingredients, and especially humidity accelerates hydrolysis (1% of the weight remains moisture no matter how much it is roasted, and it is hygroscopic). (because of the high odor), it is best to store the roasted beans in an odorless container such as an enamel container or plum wine bottle.photooxidationIn order to avoid this, glass bottles are not really suitable. If you use glass bottles, store them in a cool place out of direct sunlight.
Roasted beans need degassing during the degassing period. Roasted coffee beans are probably best left about 3 days after roasting (dark roasts are best aged for a week or more as mentioned above), as the oxidation of the aroma components progresses just right. It's the most delicious, but if you drink it before that, too much carbon dioxide will be released and the extraction efficiency will decrease, so the taste will not settle down. If you place it in a loose bottle or the like, the smoky smell on the surface will subside. This is thought to be due to the hydrolysis or oxidation of phenols on the surface. If you want to drink immediately, add a grain or two of salt to remove the smoky smell by reacting the phenols and sodium.
Also, please note that the container may explode if you completely seal a large amount of beans because carbon dioxide gas will be released for a while.
The expiration date of roasted beans is determined by the amount of carbon dioxide in the porous structure, the amount of oil with antioxidant action, the amount of melanoidin, and the amount of remaining moisture. As for the expiration date, beans that are properly roasted in a drum roaster can be drunk for about a week, dark roasts for about 2-3 weeks, and extremely dark roasts are longer than that. Also, if the roasting time is long and the Maillard reaction time is long, the individuality and aroma will be weakened, but the beans will last longer.
·blend
What is important in making a blend is whether it will suit the tastes of Japanese people and whether the beans to be used can be purchased every year. Do you come to Japan a lot? Is the quality stable? Is it compatible with the stable supply of Brazilian and Colombian beans? Is there a tendency for the price to rise because the production area is in a place that is susceptible to the effects of global warming? Etc. In addition, in order to maintain freshness, it is better not to have too many types of blends at a private store.
In addition, only 60 to 90 grains are used for one cup of blend, so even if you blend five types in a complicated ratio of 3: 3: 2: 1: 1, you will be able to achieve the desired ratio. is almost non-existent, which in addition to stochastic bias"The Brazilian Nut Effect"That is to say, when the grains are shaken in the container, the large beans have buoyancy and float to the top. If you sell the prepared liquid (i.e. coffee shop, etc.), it is better to mix it on the spot, or grind at least 5 cups at a time like an espresso grinder with a dozer and store the excess in a container with packing. When you sell beans, it's okay because it will be the center of selling.
In the case of major companies, there are more than 10 different types of beans in order to ensure a stable supply. Espresso is a drink that enjoys richness that was born from the Italian food culture that emphasizes richness, so it makes sense to blend a lot and increase the richness to a slightly excessive level for filter coffee.By the way, Italy. The Espresso National Institute (Instituto Nazionale Espresso Italiano) defines Italian espresso as a blend of five or more varieties, which Italians drink several times a day.
In that respect, Japan is not a rich culture centered on olive oil, pizza, and cheese, but a rich culture of rice miso soy sauce, so I think it emphasizes both richness and natural sweetness.
Therefore, when creating a taste that suits Japanese tastes, the first thing to consider is richness or sweetness. Then there is the vanilla scent, the fruity scent that makes you feel sour, the bitterness peculiar to coffee (not burnt), and the complex taste of richness and aftertaste. The sharpness that is the lightness of the nose, Aroma (fragrance that rises from the cup), Flavor (fragrance that flows from the mouth to the nose), and Kaeri (flavor that flows from the throat to the nose). Let's build.
Of course, the conditions are different for home use and cafe use, but I decided which vertex should be prioritized in the blended octagon below (the closer the vertex is, the more compatible it is, and the other side is less compatible, so the individuality is different). Up to 4 vertices can be produced, and the return incense is integrated into the incense.) We also refer to overseas standards such as Flavor Wheel and Flavor Tree when considering blends.
・Taste training
The best way to train your taste buds is to go to the real coffee shop and train your tongue. Let's go to three European countries, Germany, Austria, and Italy, and learn about real cafe culture and roasting. It is to know the high level of "ordinary coffee in ordinary shops" such as bars at train stations, cafeterias, and local chains. Yes, it is more delicious than Japanese specialty stores, and now (2020) there are more and more semi-automatic espresso machines in the German-speaking world, dividing the commercial market into fully automatic coffee makers that make one cup at a time. Recently, even in German-speaking countries, there are many shops that have been influenced by the third wave in recent years, and American-style coffee is also available, so you can buy such coffee in Japan. If you put the bag and beans into ziploc bags, you can bring back a lot of materials. It is a good experience to learn about the food culture and water quality over there. Recently, I can buy 100% Arabica Italian roasted beans online, so I will check it out. is also good, but you should buy beans for the local market instead of export beans, export versions for Oceania and North America are quite sour and do not meet Japanese tastes.
Personally, I use the 100% Arabica beans from KIMBO in southern Italy, which roast very deeply, as a measure of taste, probably using a Petroncini fluid bed roaster with a capacity of several tons. it might be? Of course, the roasting method and the quality of the beans change every year. may become)
It's not even a specialty bean, it's sold in local supermarkets. I'm surprised that the espresso that's been roasted a few months ago and traveled halfway around the world by sea can turn into delicious espresso. Try different certified beans in your espresso,
There are so many different qualities and roasts.
13 Hygiene management and accidents
・Hygiene management
"OccasionallyA person checking the cooling with sweaty hands and a person sorting roasted beans with bare handsHowever, since it is sterilized by heat, do not touch it with bare hands (use a radiation thermometer to check the temperature). The roasting industry is also a food processing industry, so wash your hands when working. , Wear an apron, etc., and wear a sanitary cap to prevent your hair from falling off. Please refer to "Hygiene management incorporating the concept of HACCP in the coffee manufacturing industry" edited by the All Japan Coffee Commerce and Industry Federation, All Japan Coffee Association, in accordance with the law to partially revise the
・Occupational diseases
Occupational diseases of coffee roasters are back pain and allergies. Small domestic coffee roasters are a little low in height, and you often have to bend down to check the spoon, and handling bean bags weighing 30-60kg, which can easily damage your back. It is.
As a countermeasure, raise the height of the roaster with bricks or a stand (especially if you design it so that the top of your foot can be put under the machine, the spoon will be easier to see), or divide the bean bags into small portions.
In the same way that bakeries and soba restaurants are prone to wheat and buckwheat allergies, it seems that chaff allergies are more likely to develop when chaff droplets and exhaust come into contact with the skin and mucous membranes.transcutaneous sensitizationIn particular, people with rough skin or allergies must be careful. Wear a mask, avoid touching raw beans with bare hands, and wear gloves. I've never heard of it, but it seems that people can't stop sneezing when handling raw beans.
・Work failures and breakdowns
Major mistakes include forgetting to turn off the seed light, forgetting to close the hopper, leaving the front lid open to put in the next bean, forgetting to close the opening of the cooler, etc. Let's check, the most common failures are that the shaft is scraped due to the wear of the bearings, the beans that have softened in the first half of the double roasting enter the gaps such as the front lid and harden, and foreign objects such as pebbles are caught in the gaps. If you feel something wrong, calmly turn off the power and find out the cause.
·accident
The most common accidents are fires, explosions caused by ignition caused by forgetting to turn off the gas valve, arms, gloves, or long sleeves getting caught in the rotating part of the cooler.Fires can be caused by over-roasting the beans, which can cause the beans to catch fire, or sparks falling on the cooler or cyclone chaff, or dirt in the exhaust system.
Above all, we prepare for accidents by conducting frequent cleaning, preparing fire extinguishing equipment in case of emergency, creating procedures and checklists for emergency stop of the roaster in the event of a fire, and conducting training.
In the event of a fire, immediately turn off the power to the roaster and start extinguishing the fire. When the exhaust fan is activated, oxygen is sent in, and even if the beans are put out in the cooler, they will flare up during cooling or ignite the dirt, so the damper Close the door, stop the exhaust fan, and fill the hopper with water. Be sure to have water and a fire extinguisher nearby.
Also, even if the damper is fully closed, there is always a gap through which air can flow to prevent the fire from extinguishing, so the exhaust cannot be completely stopped, so be sure to turn off the exhaust fan.
14 machinery
"When buying a machine, what is important is whether the machine can be maintained by itself." And buy from a company that can continue to supply service and parts that respond quickly in the event of a failure beyond that range.
If you are unsure about which machine to buy, you can be sure to buy a long-selling product from a major company in each field.
Whether it is domestic or imported is important, and in general, Japanese products are cheaper and are convenient for repairs, part replacements, and sales.For overseas products, Germany and Switzerland are single-phase 230V three-phase 400v50Hz, and Italy is 50Hz single-phase. Equipment developed for 220V, three-phase 380V has been adjusted as close as possible to the performance of the home country as much as possible in Japan, but in Japan, in addition to 100V in eastern Japan 50Hz and western Japan 60Hz, single-phase 100V single-phase 200V three-phase It has 200V, and it will be used in an environment with an output that is quite different from the country where it was designed, so you can't rely on its reputation overseas, so consult with an authorized distributor in Japan and choose a model after actually using it. .
・Roasting machine
Currently (2021), in Japan, Fujikoki Co., Ltd. is the representative of a small roasting machine manufacturer that comes to repair nationwide and has a high used price.Fuji RoyalFuji Royal's small roaster is equipped with a single drum and a manual damper, and the exhaust fan and cooling fan are combined into one and can be switched with a lever.
You can choose from semi-hot air, direct fire, and hot air methods, and the practical roasting amount is about 25% to 80% of the nominal amount (up to 4 kg if it is 5 kg). It is a long-selling roaster that is good at strong dark roasting.
German Probat's small machine features a powerful exhaust that uses a three-phase power supply turbofan and a double drum with punch holes on the inside, practical roasting capacity from minimum 60% to full without inverter option. Because the beans are baked almost exclusively by convection heat, the beans swell very well, and the German-style roasting is especially good for roasting before 2 cracks (the 1kg machine has no punch holes and has different characteristics).
Also, depending on the model, the ratio of conductive heat varies depending on the capacity.
We strongly recommend the domestic single drum roaster as the first one, because sales drop during the three months of summer, and it is necessary to sell deep-roasted beans for iced coffee to make up for this. It depends on people's taste preferences, but deep-roasted beans cannot be roasted with a hot-air roaster as they are with a single-drum semi-hot-air roaster.
If you want to open an Italian espresso specialty store, use a hot air double drum without punch holes that has stronger conduction heat than Probat and is suitable for rich Italian roast.Giessenor indirect hot airPetronciniIsn't it better? However, it is better not to buy a non-genuine remodeled machine from any manufacturer, because in many cases the manufacturer will not accept repairs if it has been remodeled by someone other than the manufacturer.
Also, if for some reason you buy a very old roaster or a carbon steel single drum roaster, I recommend the direct fire type.
・Grinder for sale
There are grind mortar type, cut type grinder, conical type, and roller type grinder. From espresso machines for personal use to Melitta filters, home espresso machines and mocha pots, the conical type is used for espresso. Roller mills are for factories, but there are also super high-end machines for coffee shops.
By the way, Ditting and Marcunik's shop grinders are for household espresso machines and Melitta paper filters. From the Japanese sense, they are very finely ground in countries where sales in 500g units are mainstream. Even if you buy two such as Matzer or Fuji Royal, which is specialized for Japanese paper filters, it is cheaper than one shop grinder. For commercial espresso, Markunik also has a dedicated grinder.
・Tasting coffee machine
Personally, I think that even if you don't buy a coffee machine for tasting, it's enough to make about 10 cups of large filters (less than half for tasting, so it's actually 20 cups), but if you need it, you can use a home model. There are also manufacturers that offer commercial use guarantees, so please consider that as well. I think it's better.
However, if you make a large amount at once, it will taste better than if you take a cup, and if you serve it in a paper cup, it will taste bad.
・Tasting espresso machine
Commercial espresso machines come in full-auto, semi-auto, and manual types, but in Italy (as of 2020), the northern part of Italy is strongly influenced by Austria. Refined taste to extract is mainstream, and the south is deeper
It is the mainstream to roast and mix Robusta seeds in it. The amount of powder is more and the grind is finer, and the amount of extraction is less. is often used and the atmospheric pressure is different from 12 atm.
The two are as different as the Kansai and Kanto udon broths, so choose according to your taste.
In Japan, there is no culture of standing and drinking 5 cups of espresso, which costs just over 1 euro a day, so it would be difficult for a standing cafe bar style business (most people drink cappuccino or espresso drinks while sitting down). For coffee bean specialty stores, a triple espresso machine directly connected to the water supply is probably unnecessary for tasting and sales. A machine is enough. If you ask the manufacturer, they will introduce you to a maintenance contract for both home and corporate use. Enough for the store.
I explained in detail in "How to make delicious coffee that even Salaam Kaffi professionals don't know", but the espresso machine uses copper pipes, but home use is made of aluminum pipes, so the aroma is actually better than that of commercial use. If you use it with soft water, bleaching powder will not stick to it, so it's even more difficult.) You can make milk foam with a 100-yen milk foamer and a microwave oven, so it's enough to demonstrate to customers. However, even if all the other machines are certified by the Italian Espresso Institute (INEI), the real espresso taste cannot be obtained unless the beans are roasted with a hot air roaster.
・Exhaust treatment equipment
An exhaust treatment system is mandatory in non-commercial and populated areas.
Exhaust treatment can be roughly divided into afterburners that use flames to burn off smoke and odors, electric smoke exhaust treatment equipment that uses static electricity to absorb smoke, wet roasting exhaust treatment equipment that sprays water on smoke, and filters that absorb oily smoke. The most important thing is how much the odor can be removed, so buy from a place where the manufacturer properly publishes the deodorant capacity value based on the olfactory measurement method stipulated by the Offensive Odor Control Law. (There is a difference between actual values and legal figures.) Some machines remove only smoke and can hardly remove odors. Electrostatic types cannot remove odors without an activated carbon filter, and filter types alone cannot remove oily smoke. I can barely get the smell out.
The next important thing is how much it affects the exhaust capacity of the roaster. Many processing equipment have an exhaust fan because it interferes with the exhaust, but if the exhaust fan is an inverter control type, the roasting situation Roasting is stable without being affected by clogging of the filter.
Finally, calculate the installation cost, monthly roasting amount and consumables, and also calculate the cost of cleaning and time, and decide the model.
·others
Other necessary items are a thick sealer that closes the packaging bag, a measuring instrument that is certified as a specific measuring instrument, a commercial cooler or spot cooler for summer, a gas leak detector, a moisture meter for green beans, and coffee. destoner, etc.
A TDS meter is used to check the relative quality of water.If it is displayed in ppm, you can see that there is a change when air is added to pure water by decanting. I don't know if it's blended in, but it can be used as an index.) Also, if it's just a relative value, it can be used as a coffee densitometer.
・The ultimate compact roaster
As a complete digression, I personally thought of the ultimate small roasting machine
First of all, the main body is insulated, the drum is made of single cast iron, and the amount of heat stored in the drum can be measured. The motor is a geared motor, which does not require a belt. There is a plate that can change the ratio of conductive heat and convection heat fully automatically even during roasting, and it is equipped with 4 inverters to control drum rotation, exhaust fan and cooling.
Using two fans for exhaust air, the exhaust volume can be finely adjusted without using a damper, the exhaust volume is measured with an anemometer, the bean temperature, exhaust temperature, and room temperature are also digitally recorded, and the bean temperature is fixed at the test spoon outlet. You can measure the actual bean temperature with a radiation thermometer attached (or put in the handle), and you can also attach a camera there to output an image on the screen and record the timing of roasting.
In addition, a spoon with a built-in thermometer that rotates is attached to the bearing shaft, and the bean temperature for each rotation is transmitted to the computer wirelessly in real time.
In addition, the gas pressure is also controlled by an electromagnetic valve, and except for the final roasting decision, the computer can fully automatically control the balance of heat conduction, displacement volume, and gas pressure as set in advance, and save all records. It can be shared, the operation system is not a touch panel, but switches, manual dial knobs, keyboard and mouse are easy to learn, control software runs on the browser, and above all, the body is as beautiful as a high-end audio device. I hope there is.
15 Manufacturer information and reference materials
・Mill for sale
Fuji Royal
Japan's leading company with nationwide expansion, the representative machine is the mysterious Egyptian seal R440 and R750, both of which have the same performance box type.In addition, only the R220 and R440 have a grind mortar and a cut type (no compatibility) ) I personally think that the grind mortar has a well-balanced taste.
DittingDitting
Made in Switzerland, the highest peak of the cut type that has been adopted by many famous shops, the representative model is the KFA-903, which is the finest
Turkish coffee is also available, and I personally feel that the cut type brings out the individuality of the beans.
MAHLKONIG
Made in Germany, the representative model is the VTA6S, which is used by Starbucks and other major chains.
The largest one in Guatemala for private stores, by the way, Mahlkönig, Ditting, Anfim and Hey Café are all brand names of HEMRO GROUP.
Bomback
The BM-570, a representative machine from a manufacturer often used in the Kansai region (there is also a cut type)
Karita
The representative machines of manufacturers often used in eastern Japan are the high-cut mill and the clean-cut mill, the latter being
"There is also an espresso blade."
Most of the above
・Stone removing machine/Sorting machine
Satake Co., Ltd. Fujikoki Co., Ltd.
・Exhaust treatment equipment
Fujikoki Co., Ltd. Santa Co., Ltd. and many others
·filter
Sanyo Sangyo AS Resin Three-Four Dripper Oishii Coffee Shop Coffee Filter
Melitta clear coffee filter series original natural white
Co., Ltd. Cafe Goods Cotton Power Filter Series
・Flannel fabric
Maruta Clothing Co., Ltd. Yoshida Orimono Co., Ltd., etc.
・Packaging retail
Nikonos JF Stock Pack Seiwa Package Mail Order, etc.
·soap
Asahi Kasei Frosh Perfume Free Chinoshio Oxygen Bleach
・Water purifier
Ever Pure Japan Ever Pure Mitsubishi Rayon Cleansui
The model using ion exchange resin is recommended
・Reference materials
papers and articles
・Generation of organic acids from sucrose by roasting Toshiro Nakabayashi 1978
· Changes in coffee bean structure due to roasting Toshiro Nakabayashi, Kunio Suzuki 1986
・Formation sequence of coffee brown pigments by roasting Toshiro Nakabayashi, Yasushi Yamada1987
All of Toshiro Nakamura's papers, including the above, are wonderful materials about coffee.
・Basic Chemical Reactions Occurring in the Roasting Process Carl Staub 1995
A sentence pointing out that one crack in coffee beans occurs at 180°C due to thermal decomposition of biomass
・Popcorn: critical temperature, jump and sound
Emmanuel Virot and Alexandre Ponomarenko 2015
A milestone in popcorn research that discovered that popcorn bounces at a temperature of 180 degrees
books
Taguchi Mamoru's Complete Coffee Mamoru Taguchi 2003
The Equation of Coffee Deliciousness Mamoru Taguchi Yukihiro Tanbe 2014
The science of coffee Where is "deliciousness" born? Yukihiro Tanbe 2016
Barista Bahlmann Textbook Chihiro Yokoyama 2018
・Coffee group official website
IIAC JAPAN International Cafe Tasting Association - Japan Official Website
http://coffeetasters.jp/
Roasting recording software Artisan and Cropster English official website
https://artisan-scope.org/
https://www.cropster.com
Istituto Nazionale Espresso Italiano National Italian Espresso Association official website
http://www.espressoitaliano.org/
Coffee Today Italian media specializing in coffee
https://coffeetoday.news/
The above site was very helpful as I could see information on authentic Italian espresso and profiles of roasting competitions.
In addition to this, I was able to learn many things from the books and websites of many seniors, so I am grateful.
16 Postscript
It took me almost three years to write it, but I am deeply moved to finally be able to finish it.
It has long been said by many researchers and roasters that beans explode when they reach a certain temperature. There was a lot of variation, and the chemical causes were mixed with various theories such as caramelization and cellulose decomposition. I am proud that I was able to present a hypothesis (although the student's report failed at this point...)
However, in reality, for coffee roasting researchers who make instant coffee and canned coffee at major manufacturers, this knowledge must have been a well-known fact. I feel like papers and patents deliberately make this area ambiguous.
I am not a researcher, so I cannot deny that there are some vague grounds in this book, and I think there are many mistakes, so please be patient.
Thank you very much for reading to the end.
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