Reduction in roasting weight of coffee (how much does the weight of cooked coffee beans decrease after roasting)

Reduction in roasting weight of coffee (how much is the weight reduction of cooked coffee beans after roasting) weight discount on roasted coffee beans and raw beans

Weight reduction: 15-20% weight reduction due to evaporation of water

Under this explanation, under normal circumstances, the moisture content of our coffee beans will be 10-12%.

In addition, the weight lost is generally silver, dust, material change, and the loss of carbon dioxide.

Most of the less weight is moisture.

Volume increase: due to the formation of CQ2, the volume increases by 30-60%

Composition proportion change: fat increases by 12-16%, sugar content decreases by 10%, and acid content decreases by 3%.

Reduction in roasting weight of coffee (how much is the weight reduction of cooked coffee beans after roasting) weight discount on roasted coffee beans and raw beans

Check and select the coffee again.

Caffeine: caffeine in coffee beans is an alkali. People with allergies should not consume too much caffeine. Caffeine is soluble in water, so it can be extracted from raw coffee beans in one of the following ways:

1. Water-soluble method: use a cylindrical extractor in which coffee beans are placed and treated with a water-based extraction solution mixed with saturated coffee solubilizer-non-caffeine.

2. Ethyl acetate: ethyl acetate is a solvent that can also be found in nature. Use it to wash raw coffee and extract caffeine.

3. Dichloromethane: dichloromethane is a chemical solvent that volatilizes naturally when the temperature is higher than 40 ℃; it is used to wash raw coffee to extract caffeine.

4. Carbon dioxide: under critical conditions (gas / liquid, pressure = 250bar), carbon dioxide (CQ2) acts as a solvent to wash raw coffee and extract caffeine.

Production process: first put a small fire lamp on the water rack into the siphon coffee pot to grind the coffee beans, put the ground coffee powder into the upper pot as the water temperature rises below, the steam pressure causes the water to rise through the pipe and merge with the coffee powder in the upper pot. After mixing the coffee powder and water evenly with a small stick for a period of time, remove the small fire lamp under the pot to cool the air in the next pot. Vacuum can give the necessary assistance, that is, wrap the next pot with a wet towel to help the kettle cool. At this point, the coffee liquid will return to the bottom pot through the filter cloth, so that the coffee will be cooked.

Reduction in roasting weight of coffee (how much is the weight reduction of cooked coffee beans after roasting) weight discount on roasted coffee beans and raw beans

Coffee has different baking time according to different varieties. What is made from lightly roasted coffee beans is the so-called white coffee. This kind of coffee is less popular and is a Malaysian specialty. At that time, I was curious and bought and drank it online, and it tasted good. The following Mantenin coffee has been roasted for a long time, the color is shiny, and when the beans reach about 400 degrees Fahrenheit, they will turn dark brown. At this time, the coffee beans begin to produce oil, a process called high temperature decomposition, when the roaster has to decide whether to continue baking, timing is very critical, once overroasted, the coffee beans will be destroyed.

A series of chemical changes occur in the process of baking. After about 5-25 minutes of baking (depending on the temperature selected), the green coffee beans lose some humidity and turn yellow. In this process, the coffee beans will swell, changing from a strong, high-density raw bean to a low-density fluffy state. After this process, the coffee beans will about double in size and begin to show a light brown after stir-frying. After this stage is completed (after about 8 minutes of baking), the calories will be reduced. The color of the coffee soon changed to dark. When the preset baking depth is reached, cold air can be used to cool the coffee beans in order to stop the baking process.

Baking is roughly divided into shallow baking (Light), medium baking (Medium), urban baking (City) and deep baking (Deep). Light roasted coffee beans: will have a strong smell, very crisp, high acidity is the main flavor and slightly mellow. Medium-roasted coffee beans: have a strong mellow, but also retain a certain degree of acidity. City-baked coffee beans: the surface is dark brown, the acidity is replaced by slight bitterness, and most of the flavor has been destroyed. Deep-roasted coffee beans: dark brown in color and oily on the surface. For most coffee beans, the alcohol content increases significantly and the acidity decreases. In fact, roasting coffee is a way of processing food. The roasting of professional coffee is the personal expression of the roaster. Just started to contact with professional coffee.

Reduction in roasting weight of coffee (how much is the weight reduction of cooked coffee beans after roasting) weight discount on roasted coffee beans and raw beans

The biggest problem with coffee beans with different roasting degrees (SPCIAITYCOFFEE) is the name of the roasting degree. For example, CITY, FUIICITY, FRENCH, ESPRESSO, etc., all produce different baking colors because of the different baking machines and producing areas. In addition, some roasting levels are named after mixed coffee: for example, ESPRESSO is a coffee with a specific roasting degree for making ESPRESSO, and even if the color looks the same, it may have a completely different flavor. Therefore, the selection of the type of beans, baking temperature and baking method, and the length of baking time are the main factors that determine the final flavor.

When you grab a handful of raw coffee beans and smell it, there is always a pungent smell, which is very different from the charming smell of coffee in your impression. However, after roasting "fragrance" correctly, raw beans will emit the strongest aroma in the world. The small, high-altitude raw Arabica coffee beans are like a warehouse full of chemicals. At present, scientists have identified more than 2, 000 known ingredients, of which 70 to 850 are aromatic ingredients, which can be called the most fragrant in the human diet. There are only 150 kinds of vanilla used for seasoning in the catering industry, and the mellow composition of wine is not nearly as rich as coffee.

Roasting awakens fragrant elves however, the 700 or 800 fragrant "elves" contained in raw coffee beans will not come out on their own, but must be "awakened" by professional baking. Without this procedure, coffee can only be tasted in the sun or washed in water, and it smells uncomfortable, let alone drink it. After five to 25 minutes of heating, the chemical composition of raw beans has undergone drastic changes, giving off a rare fragrance in the human world. This complex chemical reaction cannot be simulated even in today's most sophisticated laboratories, but it can probably be summed up into several key items.

First of all, after baking raw beans at more than 200 degrees Celsius, the moisture begins to evaporate, the volume expands by 60%, and the weight is reduced by 10% to 25. Depending on the degree of baking, the deeper the baking, the greater the weight loss. No wonder many operators do not like re-baking to save costs. Another important phenomenon is exhaust. Raw beans release carbon dioxide during baking and will continue to exhaust for 30 days after baking. Interestingly, the emission of carbon dioxide is conducive to the preservation of coffee beans, because during the exhaust process, oxygen molecules are not easy to invade, that is to say, the oxidation that destroys the flavor of coffee cannot be carried out. However, the exhaust gradually slows down after seven days of baking. Oxygen molecules are easily attached to the bean surface, and the flavor of coffee decays quickly, which is an important reason why coffee beans should be used up within a week after opening. Roasting secret: getting the highest caramelization and the least caramelization is the link that affects the coffee flavor the most. After roasting for six to seven minutes, raw beans absorb a lot of heat, start the pyrolysis reaction, and make the first explosive sound. Some sugars are converted into carbon dioxide, water continues to evaporate, and new aromatic components gradually develop to form the so-called coffee oil. And combine with hundreds of aromatic substances such as nicotinic acid, citric acid, quinic acid, malic acid, acetic acid, caffeine and so on. The pyrolysis reaction can last until the second explosion. Although caramelization is an important process to awaken aromatic elves, with the prolongation of baking time, some ingredients will also be carbonized to form bad astringent substances. How to obtain the highest caramelization and minimize carbonization at the same time seems to be the biggest challenge for bakers.

Pay attention to the changes in sound, color and taste. The above chemical reactions can be judged by listening to the sound, seeing the color and smelling the smell. As the color of coffee beans continues to heat up, the color of coffee beans will change from gray to golden yellow to light brown, then to a trace of reddish brown of oil, and then a large amount of oil will show a dark brown of oil. if it continues to bake, the coffee oil on the bean surface will dry out and appear dead black. and emit a lot of blue smoke, with a burning smell, this is a warning that is close to the burning point. Prepare to call 119 to help put out the fire. Experienced bakers will choose between light brown to oily dark brown for safety. Coffee beans change from shallow to deep because of changes in caramelization and acidity.

Listening to sound is also the basis for judging the degree of baking. If the temperature of the roaster is hot enough, coffee beans will burst twice during the baking process. For example, heat-resistant raw beans such as Mantenin and Angelica will burst for the first time in about seven minutes, and the sound will be low and sparse. This means that the "pyrolysis" starts, that is, the starch begins to be converted into caramel, and water is ejected from the bean table with carbon dioxide, making a low popping sound, which is quiet for two minutes. At about 12 minutes, there was a more violent and sharp burst, which was the sound of broken fibers in coffee beans, which indicated that the baking was coming to an end, and the fragrance would fade if it went on. We can see that coffee beans can talk. In addition, Brazil and Java and other less heat-resistant beans, the first explosion and the second explosion came earlier, the heat control should pay special attention.

Reduction in roasting weight of coffee (how much is the weight reduction of cooked coffee beans after roasting) weight discount on roasted coffee beans and raw beans

Use the data to define the roasting degree to understand the "virtue" of coffee beans during roasting, and then talk about the definition and taste of various roasting degrees. In the United States, the degree of roasting has long been defined by Cinnamon (shallow roasting), City (shallow roasting), Fully City (deep roasting) and Dark roast (heavy deep roasting, including Italian and French). However, the American preference for coffee flavor has always been rich in the west and light in the east, so the shallow roasting on the west coast may have reached the deep roasting level on the east coast, and vice versa, so these terms still belong to their own tune and are not scientific. In recent years, the American Fine Coffee Association has strongly advocated the caramelization value (Agtron number) to determine the baking degree, using the red inner line to determine the caramelization degree of coffee beans. The higher the value, the lower the caramelization, that is, the shallower the baking degree, and the lower the value, the deeper the caramelization, that is, the deeper the roasting degree. With the data, you can more accurately understand the roasting degree of coffee beans, so that the shallow roasted coffee in the United States and the West will not become a joke of re-roasting coffee in the East. This is a good evolution.

Seattle Gourmet Coffee also uses this set of scientific standards to define the degree of roasting. Caramelization value above 70 is the shallowest roasting, Cinnamon,60 above is shallow roasting around City,40, or so-called Fully city, and below 35 is heavy and deep roasting, including French roasting and espresso roasting. The flavor of coffee also varies with the degree of roasting. Generally speaking, the sour taste is inversely proportional to the degree of roasting. If you prefer sour taste, you might as well buy coffee with a lighter roasting degree. If you like the thick and sweet taste, you can choose heavy roasted beans. In addition, the caffeine content is inversely proportional to the degree of roasting, that is to say, light roasted coffee contains more caffeine than re-roasted coffee. Because caffeine can be destroyed during baking. The fruit aroma will also decrease with the deepening of roasting degree, but the fermented flavor, choking taste and sweet taste of mellow wine, light roasted coffee is not easy to develop, re-roasted beans have more advantages in this aspect. However, if the rebaking technique is not good, it is likely to produce a stove of rotten coffee that is scorched and bitter.

Shallow baking and deep baking, noisy! Whether coffee should be roasted lightly or deeply is the most controversial topic in the industry, even to the point of falling out. Generally speaking, the degree of roasting in Northern Italy and the eastern United States is relatively shallow, and the caramelization value is mostly around 40. The well-known producers of this school include Illy Caffe, Green Mountain and Vivace Espresso (note: although the company is based in re-roasted Seattle, it goes against the trend and advocates shallow roasting), and the coffee beans of these companies immediately cease fire before the second explosion or before the coffee oil is about to seep out of the table. Their argument is that coffee oil contains a lot of aromatic ingredients and should be preserved in beans as far as possible. Coffee oil seeps out. Although the oil looks good, the aromatic components are also lost. This pie also believes that the coffee beans are baked immediately before the oil comes out, the caramelization degree is the best, the Body (consistency) is also the best, and the acidity and taste of the coffee are the most balanced. The shallow Bakery Group also attacked the re-baking industry for baking coffee oil out of the bean table as a disaster.

However, the re-baked pie in southern Italy and the west coast of the United States, such as Peet's Coffe in San Francisco and Caffe' coffee in Seattle, is 39 Arte), and Coffee beans and Machinery Company (Beans and Machines), however, insist that coffee beans must be roasted out of oil in order to taste good. Their beans have been tested that the caramelization values of beans for espresso are all below 35, and the sour sweet potato is even overbaked at 18 degrees, which is really to the point of "heavy baking, hands are not soft". Most of this pie glided for a while after the second explosion or the appearance of the bean oil. They did not agree with the shallow baking pie's so-called "loss of aroma components" and criticized the shallow baked pie's beans as "underdeveloped." the sharp sour taste seems to outweigh the sweetness and lacks the choking taste, and the flavor is too monotonous. They even ridicule that the real purpose of shallow baking pie is to save money, because only top Arabica beans can withstand heavy baking and develop an excellent flavor that is rich, choking, sweet and does not bite the throat. will only show a monotonous bitter taste.

The heavy baking pie also calls itself the "glutton coffee that walks the edge of the razor." because the coffee beans change so quickly after the second explosion, the whole furnace will be reimbursed for the slightest mistake, unlike the shallow baking pie, which "withdrew its troops" before the oil burst, and the technical level is relatively low. Bitz coffee, which advocates heavy roasting, enjoys a high status in the coffee industry in the United States. Bitz can produce beans at a high temperature of more than 200 degrees Celsius and operate the oven for more than 15 minutes, and it is thick but not bitter. This work is admirable. Of course, this has something to do with Bitz's ability to refit the roaster. In short, the heavy baking pie insists that only the beans after the second explosion, the flavor is complete. To be fair, light roasting and deep roasting have their own advantages, and drinking coffee is already highly subjective and should respect each other. Fortunately, the dispute in Taiwan's coffee industry is not as obvious as that in the United States. Each has its own insistence on fast and slow stir-frying, in addition to the degree of baking, even the roaster has its own views. At present, there are two major types of professional roasters, one is the traditional rotary furnace (Drum Roaster), and the other is the newly emerging hot gas furnace (Hot Air Roaster). The former uses gas to heat the bottom of the furnace, while the metal blades in the furnace keep stirring the beans, while the latter uses high-temperature hot air to bake the beans. Because of the strong air flow, the beans in the furnace keep flying, so there is no need for leaves to stir the beans. It takes a long time to bake beans in a converter, which is generally called slow stewed pie, while the speed of baking beans in a hot gas stove is faster, which belongs to fast fried pie. The industry is red-faced over the merits of these two kinds of roasters, and it is also described as a "war between slow stew pie and fast stir-fry pie." slow stew pie prefers the traditional rolling furnace, believing that it should be roasted at a warm temperature at first, and then slowly increase the heat after an explosion, so that the water in the beans can be prevented from evaporating too fast, and the damage to the cell tissue can be minimized. Only by heating step by step can the flavor of coffee beans be fully developed. Those who advocate slow stewing are mostly famous glutton coffee, such as Bitz, Vivac, Allegro and coffee bean and machine companies.

Reduction in roasting weight of coffee (how much is the weight reduction of cooked coffee beans after roasting) weight discount on roasted coffee beans and raw beans

Their baking time is about eleven to 25 minutes. Interestingly, the scale of slow speculators is relatively small, emphasizing a small amount of baking, disdain to win by quantity, careless speculation. Fast fried beans have a strong sour taste, while slow fried beans prefer to use a hot stove. They think that strong hot air flow, better heat conduction and average heating of beans can achieve the desired baking degree in the shortest time, thus reducing the disappearance of coffee oil and damage to cell tissue. The baking time is mostly within three to fifteen minutes. Since quick frying saves time and less weight loss of coffee beans, you can save money, so most of the heat stove operators are large baking companies that win by quantity, and most of the coffee from Burger King and McDonald's in the United States is produced by heat stove operators. Generally speaking, the sour taste of fast fried beans is more obvious, but also more layered, but slow fried beans suppress the sour taste, drinking is relatively low and sweet. The relationship between fast and slow stir-frying and chlorogenic acid plants contain bitter and strong chlorogenic acid "Chlorogenic acids" to resist insect pests or bacteria. Coffee raw beans also contain a lot of chlorogenic acid, which has something to do with the green-blue color of raw beans, and the content of chlorogenic acid is also proportional to caffeine. Low-altitude robusta raw beans have more caffeine than high-altitude Arabica beans, so the content of chlorogenic acid is also higher. Studies have shown that Robusta contains 10% chlorogenic acid, while Arabica has only about 6%. No wonder Robusta has a bitter taste. Chlorogenic acid is a kind of organic acid with the highest content in raw beans, and it is also the original culprit that causes the acidity and bitterness of coffee. Fortunately, chlorogenic acid will be destroyed in the baking process. More importantly, the degree of chlorogenic acid disintegration is inversely proportional to the baking speed, that is to say, the faster the baking, the more chlorogenic acid remains, the slower the roasting, the less the residue. This is enough to explain why quick fried beans drink more tart while slow fried beans have a smoother flavor. Therefore, espresso beans are more suitable for slow frying. If you stir-fry espresso in a hot stove at 300 to 400 degrees Celsius, a second explosion may occur in less than three minutes. However, too much chlorogenic acid will make espresso sour too sour.

Reduction in roasting weight of coffee (how much is the weight reduction of cooked coffee beans after roasting) weight discount on roasted coffee beans and raw beans

The relationship between baking and high-quality acids in addition to inferior chlorogenic acid, raw beans also contain a lot of high-quality acids, including citric acid, malic acid, acetic acid, phosphoric acid and quinic acid. In addition, other organic acids will be born with the disintegration of carbohydrates in the baking process. At present, as many as 34 kinds of organic acids have been determined, of which 15 are volatile. In principle, the concentration of high-quality citric acid, malic acid, phosphoric acid and acetic acid is the highest in moderate baking and decreases with heavy baking. Organic acids have a great impact on the flavor of coffee. Interestingly, the pleasant and lively acid of light-roasted coffee is the overall expression of more than 30 organic acids, any one of which is particularly prominent and will have a bad taste. Coffee roasting is a great learning. the age, density, hardness and moisture content of raw beans should be taken into account. even the relative humidity on the day of roasting, cloudy, sunny, rainy, temperature and wind changes can not be ignored. So the baker is not only an artist but also half a scientist!

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