Roasting determines the taste of coffee

Generally speaking, each coffee cherry contains two raw beans, and the fragrance is still hidden, waiting to be discovered. In raw beans, it contains a lot of chloric acid. As the baking process, chloric acid will gradually disappear, releasing familiar and pleasant fruit acid-such as acetic acid, citric acid, malic acid in wine. Baking is just right, can present these beautiful sour taste moderately; on the contrary, if the baking is too much, it will completely cover them up.

Baking decides the taste.

A book about coffee says,'80% of the taste of coffee is determined by the bakering.' We don't know how this percentage is calculated, but the importance of baking in coffee production is not exaggerated.

Baking, as the name implies, is to provide heat to coffee beans, and to produce chemical changes in the internal structure of coffee beans by heating, that is, heating converts starch in raw beans into sugar 5 or acidic substances at high temperature. substances such as cellulose will be carbonized to varying degrees by carbon, water and carbon dioxide will be evaporated, proteins will be converted into enzymes, and the remaining substances of fat will be combined. An oil film is formed on the surface of coffee beans.

The main purpose of baking is to produce this aromatic oil, which is called coffee oil, or, more accurately, coffee oil, which gives coffee beans a strong aroma. This aromatic oil is volatile, that is, it is the main factor that brings flavor and fragrance, and they can accommodate water, which means that people can enjoy it in a cup.

Baking must be uniform, the most important thing is to be able to stir-fry the beans evenly inside and outside. At first, the water in the coffee beans should be discharged smoothly by fire. if only fast and uneven is required, it may cause the beans to have a beautiful appearance but a light internal color, and has not yet begun to decompose. The deep, medium and shallow companionship of beans during baking is decided and controlled by people, and even there is a knack for cooling beans before the end of baking. If the temperature is not cooled quickly, the heat contained in beans will make the beans darker and greasy, and the taste will become bitter.

Baked coffee beans swell, a bit like popcorn, and crackle during baking, just as we make popcorn in a microwave oven.

The color of roasted coffee beans changes from light green to tea brown, which can not only change the unique color of amber, flavor and aroma, but also volatilize the sour, sweet, bitter, mellow and fragrant five obvious taste characteristics of coffee. If the baking technology is good, the beans will be large and expanded, no wrinkles on the surface, uniform luster and each has its own different flavor.

Shallow baking. Moderate baking. Deep baking

The baking of coffee beans can be divided into shallow baking according to the degree of baking. Moderate baking. There are three categories of deep baking. Generally speaking, the light baking color is lighter, the sour taste is strong, and it has a unique flavor.

The only common term among coffee bakers is bottom, medium, and deep. Or sometimes use light, medium and black, which have different meanings for different kinds of coffee.

Shallow baking

Shallow accompany, such as cinnamon baking, has a more meticulous and mild aroma.

There are a few different words for this kind of baking. Light is mild, Half City is half-city, and in the United States, people often use the word city to refer to coffee baking, Cinnamon cinnamon or light brown NewEngland New England style-this is the lightest kind of baking. Cinnamon is usually a high degree of baking in this category, and the beans baked in this way usually have a sour taste. When the beans make the first light sound and the volume expands at the same time, the color changes to a delicious cinnamon color, so it is also called cinna-mon roast or half-city roast. Acidity dominates the flavor of shallow accompany beans, and the texture and taste have not been brought into full play, so they are generally used as canned coffee, which can not meet the real coffee experts.

Moderate baking

Chinese accompany, also known as' urban baking'or 'American baking', is more mellow. There are the following, Full City, American American, Medium medium, High depth, Breakfast Breakfast Regular regular Brown Brown.

When baked for 11 minutes, the coffee beans show an elegant brown color. New Yorkers like to start the day with coffee beans and Shannon's milk and sugar at breakfast, so this method of baking is also called breakfast roast or city roast. Chinese companion can not only preserve the original flavor of coffee beans, but also moderately release fragrance, so Nanshan, Colombia, Brazil and other individual coffee, choose this way of roasting.

At 12 Mel for 16 minutes, the oil began to surface, and the beans were burnt into an oily dark brown, called full-city roast. Some people think that at this time, the sour, sweet and bitter taste of coffee reaches the most perfect balance, and the characteristics of coffee beans are clearly depicted.

Among these moderate baking degrees, Medium is very sour and mellow, which is the most suitable for making comprehensive coffee. High coffee beans have the most mild sour taste and a touch of bitterness, which is suitable for Nanshan Coffee and is deeply loved by Japanese and European consumers. Flavors such as city, which are more bitter than sour, are suitable for Colombian coffee or Brazilian coffee. For city-flavored coffee, the higher the degree of baking, the higher the bitterness will cover the sour taste. South Americans usually like the bitter city taste, while Americans like to use this coffee to make summer ice drinks.

Deep baking

Among them, the French-baked coffee beans will have a kind of black dark brown on the surface, while the Italian-baked coffee beans will have an obvious glossy surface. Espresso is usually made from deep-roasted coffee, on the one hand, to taste the coffee after adding milk, cream, or chocolate, and the strong flavor of a small amount of coffee can also help people drink less.

Deep baking, the darker the color of coffee beans, sweet flavor, oil has been turned into caramel, bitterness. Endless aftertaste, the most suitable for brewing strong Italian espresso, so it is also called Italian baking method.

Moderate baking gives coffee beans life and turns into an intriguing sour, sweet and bitter taste. However, people who are sensitive to caffeine should choose the beans that accompany them as much as possible, because during the baking process, the caffeine will slowly disappear, so the deeper the beans, the lower the caffeine content. It is said that the caffeine content in each cup of Italian thick-locked coffee is only half that of other baked coffee.

The color of beans baked in Vienna is darker than that in Chinese, while French baking, Italian baking and mainland baking are dark brown, close to black, producing attractive mellow bitterness, such as espresso.

Extra-deep baking

There are usually Dark French (Deep French) and Heavy (extra heavy flavor). This is often to satisfy the hobbies of some special coffee lovers, and some people bake this bitter coffee at home, with a faint smell of cigarette ash.

Metropolises all over the world have their own preference for baking. In Tokyo, micro-deep moderate baking (high-roast) is more popular, but gradually tends to deep baking, while Brazil has always been more popular.

And New York, as its name, generally prefers city roast, but because the city is inhabited by a variety of different races, it also sells a variety of coffee beans with different degrees of roasting. Vienna, on the other hand, prefers deep-baked full-city roast. And more like its name, the French prefer French-style baking, while the Italians often use Italian-style baking.

However, in recent years, people in Europe and the United States have widely used German (high-city) and dark (the most commonly used deep baking in Brazil and Italy), and the changes are also colorful, while the coffee made by steam pressurizer is still popular.

No one can answer why you can't mix "light" and "black" coffee. If you want to do that, you should keep in mind that some toasters are not suitable for baking some coffee, just as some coffee is suitable for drinking at different times of the day. For example, deep-roasting Ethiopian coffee beans would be a waste because it would lose the characteristics of the coffee.

On the other hand, when some coffee beans are baked in black, they will produce new and interesting qualities, such as Mexican coffee beans that produce an interesting sweetness when baked in black.

But some coffee beans, such as Guatemala Antigua coffee beans, retain their sour and fruity flavor when they are deeply roasted, which is more difficult for other coffees. In addition, Sumatra coffee beans are usually full-grained, but are lower than medium acidity and lose acidity when roasted deeper and tend to become sugar paste.

Gas baking with charcoal fire baking with infrared baking

According to the different heat sources used, the baking of coffee can be divided into gas baking, charcoal fire baking and infrared baking. One of the most commonly used is gas baking, the temperature is controlled between 200 Mel and 300 degrees Celsius, and the temperature should be adjusted from time to time according to the need.

Most baking stoves use gas, the temperature is about 290 degrees, in the first 5 minutes, the free water is evaporated. The remaining water is then squeezed out of the beans (the process produces a "crackling" sound "fluffy" sound.

When the coffee beans reach about 200 degrees, they turn dark brown and begin to produce oil, a process called high temperature decomposition. At this time, the decision made by the coffee baker in the operation is very important, because if the baking time is too often, the coffee beans will be destroyed.

Commercial baking furnaces mostly use large machines. Generally, it is a cylindrical container with a diameter of more than two meters, with a heat source at the bottom, and a mixing tool inside the container constantly stirring the coffee beans. at the same time, the container containing the beans is easy to rotate, so that the coffee beans are heated evenly, and the coffee beans rotate along the spiral groove in the drum. When it reaches the trough low, it begins to bake. This expensive machine is used only when baking a large number of coffee beans.

Professional bakers may use a special barbecue. It is generally bulging, rotating horizontally, the fire is located in the lower part, and has an exhaust fan to drive away the smoke.

The necessary equipment for baking

1. Baking room: dust, silver, smoke, etc. discharged from the baking company are easy to dirty the environment, so although the space is narrow, it is best to have a baking room, the ventilation of the baking room must be considered.

two。 Dust collectors, in order to prevent the formation of public hazard problems, should at least be equipped with dust collectors such as dust separators.

3. Baking machine exhaust chimney: dust collector to the top of the chimney, it is best to set higher, in order to avoid interference to nearby residents. Because if the chimney is too bottom, the combustion of the baking machine will be worse, resulting in the stench of smoke guns.

4. Raw bean cleaner (baking machine sharing): there are often all kinds of side articles on raw beans. Inclusion, so the cleaning operation must be carried out before baking. If a special cleaning machine cannot be set up, it can be done with a baking machine. The method is to put the raw beans into the unheated baking machine, and then set the air flow regulator to exhaust, turn on the baking machine to let him rotate, you can clean things other than raw beans. This method is suitable for naturally dried raw beans. Old beans. And baked beans are particularly effective.

5. Cooler: there must also be a special cooler which can cool it all at one time with the maximum amount of promised baking machine. There is a convenient way to take up less space. Is to choose a baking machine and a cooler in one.

6. Air-conditioning equipment: when the temperature rises in summer, coupled with the release of hot air, the room temperature will increase, thus reducing the cooling capacity of baked beans, in which case air-conditioning equipment is needed. and it is best to set it in a position that can be shared with the inlet of the cooler.

Smaller retailers may use a 12-kilogram machine.

In the baking process, it is very important to keep the coffee beans moving, not only to ensure the smooth operation of the machine, but also to prevent the coffee beans from burning.

When the coffee beans are taken out of the stove, most of them cool naturally, sometimes with water, the faster the better, because the roasted coffee beans will continue to be processed after cooling.

Manual baking

When it comes to companionship, the layman always thinks it is difficult. But as long as you can really grasp a few key points, it will be very difficult not to return. At the beginning, you may not be able to stir-fry well, but after you are proficient, you can skillfully add or subtract Chengdu according to your own preferences.

Here we will introduce you to the "manual baking" method of using hand strainer:

1. Buy a filter with a handle. The best choice of raw coffee beans is Central and South America series (Peru. Cuba. Mexico. Brazil and other real estate), the book is more suitable for beginners. Pick out the weak beans by hand to ensure the quality of the city.

two。 Put 100 grams of raw beans into a strainer with a handle and close the lid. Pan-fry and stir-fry over medium heat to keep the heat stable, hold the filter screen at the top of the fire about 20ml / ml 30cm, repeatedly and evenly swing around to make the moisture evaporate.

3. Coffee beans are all baked by the fire, let the fire roast evenly to every corner of the filter, prevent the beans from burning, concentrate on swinging the filter. After the water evaporates, there will be changes in smoke, color, taste, sound and so on. After baking for 6 minutes, the beans will turn to a light brown color.

4. Eight minutes later, when the 'first burst' began, the coffee beans doubled in size and crackled. After the sound disappears, the taste of 9 (depending on the type of coffee) coffee beans is released after baking in the container for 10 or 15 minutes, and most of these flavors are balanced, and then "the second explosion begins." this marks the end of the baking process of coffee beans.

5. After opening the lid and pouring the coffee beans into a plate or sieve, the whole air is filled with the smell of coffee beans, and then cool them quickly with the cold air of a fan or hair dryer. The weight of roasted coffee beans will be reduced to about 85 grams.

6. I feel that I can roast the coffee with a strong sweet taste.

After baking, once again confirm the unbaked beans and the unbaked beans, remove them if any, and store the fried beans in a bottle or jar for 1-2 days.

Baked coffee beans can be stored at room temperature if they are to be used in a week. The best way to keep them is to keep them sealed in the refrigerator. Just take out the necessary amount and grind them each time you use them. It takes about two weeks to maintain the inherent flavor of coffee beans.

You need to pay attention to some key points in the baking process.

Second, do not bake quickly with a strong fire, because the baking is excessive, and the bean heart burns with bitterness, so be patient.

Third, during baking, there will be thick smoke and fragrance, and the skin of coffee beans will bloom at the beginning. So you should cover the gas stove with aluminum foil in advance, and you can also bring the gas stove to the outdoors to enjoy the fun of baking coffee beans.

Fourth, the biggest enemy of coffee beans in baking is oxygen and light (even in dim light); because once coffee beans are baked, the aroma produced on the surface of coffee beans will soon disappear, and the oil precipitated from the surface of coffee beans will be oxidized. And then produce the smell of coal and rot.

Fifth, the baking appliances themselves can also produce great destructiveness. If the coffee beans are not baked to the necessary temperature or long enough, the oil will not ooze, and if the temperature is too high or too long, the taste will fade and have a scorched smell. Burnt coffee is always unpleasant.

If roasting coffee beans is very good, it will also become an art. In the process of roasting, coffee beans will produce a variety of flavors and fragrances. Without this process, the coffee in the cup will be obviously insufficient.

Chemical reaction of Coffee in roasting

Coffee has a rich, wide range of flavors. Coffee produced in different regions, different elevations, different climates and different producing areas has its own unique characteristics. Raw beans are fragrant and have no usual coffee taste at all; the taste of coffee comes from proper roasting. Show fruity (light roasting) or caramel sweetness (deep roasting). The shallower the baked, the more sour the taste, and the deeper the baked, the more bitter the taste.

Raw beans in high temperature environment, through thermal decomposition, coffee raw bean components such as chlorogenic acid, protein and fat undergo a series of chemical changes (mainly Mena reaction) to produce coffee aroma substances. including aldehydes, lipids, ketones, acids and so on.

The relationship between the changes of material properties and temperature in the process of thermophysical and chemical decomposition of coffee beans before and after baking:

When the bean temperature > 100℃, the color of raw beans changes from green to yellow, and when the moisture is on, it is lost for dehydration, resulting in a smell similar to that of baked bread.

Bean temperature > 120,130 ℃, raw bean color changes to light brown.

The bean temperature is about 150℃ to produce the smell of stir-fried barley.

The bean temperature is about 180 ℃ and begins to produce green smoke. The first explosion begins to produce chemical pyrolysis reaction, which releases a large amount of CO2. The burst sound occurs, the color turns brown, and the size of the bean increases.

The bean temperature is about 210 ℃, the first explosion is over, and the color continues to darken.

The second explosion of the bean temperature was about 220℃ ~ 230℃. The color continued to become dark and dark brown, and oil appeared on the surface of the coffee bean.

The bean temperature is about 240℃ ~ 270℃. Although the temperature increases, the darker the bean color, the more gas is released, the volume continues to expand, the coffee bean surface oils out, and the coffee aroma changes fully.

The bean temperature is about 270℃ to stop releasing smoke, the color is black, the appearance becomes dark, and the volume is no longer larger.

The bean temperature is about 300 ℃. The beans are black, puffy and fragile, and the aroma disappears completely and becomes carbonized.

The general actual baking temperature range is 185-240 ℃. In addition to the influence of temperature on the flavor of coffee, the way and equipment of roasting also have an effect.