What baking degree do you choose? The deeper the baking, the stronger the bitterness; the lighter the baking, the more sour.

Every coffee bean contains fragrance, sour taste, sweetness and bitterness. How to release it incisively and vividly depends on the skill of baking.

The process and stage characteristics of coffee roasting

The flavor of coffee depends not only on the variety of coffee, but also on roasting. Basically, the roasting of coffee is a kind of high temperature coking, which completely changes the substance inside the raw bean, produces a new combination, and recombines to form aroma and mellow flavor. This effect will only occur at high temperature. If only low temperature is used, it will not cause decomposition and coffee beans will not be cooked no matter how long they are roasted.

I. Baking process

Most people think that baking is nothing but cooking the raw beans with fire. In fact, in the process of coffee processing, roasting is the most difficult step, it is a kind of science, but also an art, so in Europe and the United States, experienced bakers enjoy a highly respected status. Baking can be divided into the following three stages:

1. Drying

In the early stages of baking, raw beans begin to absorb heat and the water inside gradually evaporates. At this time, the color gradually changed from green to yellow or light brown, and the silver film began to fall off, you can smell a faint smell of grass. The main function of this stage is to remove moisture, which accounts for about half of the baking time, because water is a good heat transfer conductor and helps to bake the internal material of coffee beans. Therefore, although the aim is to remove water, the baker will make good use of the temperature of the water and properly control it so that it will not evaporate too quickly; in general, it is best to control the water to reach the boiling point and turn into steam in 10 minutes. At this time, the internal material is fully cooked and the water begins to evaporate, rushing out of the outside of the coffee beans.

2. High temperature decomposition

When roasted to about 160 degrees Celsius, the water inside the beans evaporates into gas and begins to rush out of the outside of the coffee beans. At this time, the interior of raw beans changed from endothermic to exothermic, with the first bursting sound. After the bursting sound, it turns to endothermic, when the pressure inside the coffee bean is extremely high, up to 25 atmospheric pressure. High temperature and pressure began to deconstruct the original tissue to form new compounds, creating the taste and taste of coffee; at about 190 degrees Celsius, the transition between endothermic and exothermic took place again. Of course, high temperature cracking continues to occur, coffee beans from brown to dark brown, gradually into the stage of re-baking.

3. Cooling

Coffee must be cooled immediately after roasting, quickly stop the pyrolysis at high temperature and lock the flavor. Otherwise, the high temperature in the beans will burn off the aromatic substances if they continue to act. There are two cooling methods: one is air-cooled and the other is water-cooled. The air-cooled type requires a lot of cold air to cool the coffee beans quickly within 3-5 minutes. In the field of professional baking, large roasters are equipped with a tray with a rotatable driving arm; when the baking is completed, the beans are automatically fed into the tray, and the fan at the bottom of the tray is immediately activated to blow cold air. And the pushing arm stirs the coffee beans for cooling. Although the speed of water cooling is slow, it is clean and non-polluting, and can retain the aroma of coffee, so it is used by selected coffee industry. The water-cooled method is to spray a layer of water mist on the surface of the coffee beans, allowing the temperature to drop rapidly. As the amount of spraying water is very important, it requires precise calculation and control, and will increase the weight of baked beans, which is generally used in large-scale commercial baking.

2. Baking degree and characteristics

In terms of baking degree, the deeper the baking degree, the stronger the bitterness; the lighter the baking degree, the stronger the sour taste. The choice of baking degree depends on the characteristics of the coffee bean itself. For the coffee beans with strong bitter taste and light sour taste, the moderate and shallow roasting degree is generally chosen.

1. Shallow baking (Light)

The most mild fried culture, no flavor and concentration to speak of, the beans are not ripe, with the green taste of raw beans, not suitable for grinding and drinking. It is generally used as an experiment.

2. Deep shallow baking (Cinnamon)

Also known as cinnamon baking, for the general popular degree of frying, leaving a strong sour taste. The color of beans is quite similar to that of cinnamon, so it is also called cinnamon baking and has a sour taste. It is favored by people in the western United States.

3. Shallow medium baking (Media)

The color deepens, easy to extract the original taste of coffee beans, mellow, sour and delicious. It is mainly used for mixing coffee.

4. Medium baking (High)

Coffee has a stronger flavor and a lighter sour taste, which is the general way to roast coffee beans. The sour taste is neutralized and bitter, suitable for coffee such as Blue Mountain and Kilimanjaro. It is loved by Japanese and Nordic people.

5. Deep medium baking (City)

Also known as city baking, bitter taste is stronger than sour taste, almost no sour taste, unique flavor. Coffee suitable for Colombia and Brazil is very popular in New York.

6. Normal baking (FullCity)

Also known as city-wide baking, suitable for brewing iced coffee. No sour taste, mainly bitter taste, bitterness will be aggravated, but high-quality beans will have sweet taste. Used for iced coffee, preferred by people in Central and South America.

7. French baking (French)

French baking method, slightly black color, strong bitter taste, but also ooze oil, bitterness and concentration are deepened. Coffee used for steam pressurizer.

8. Deep baking (Italian)

Also known as Italian baking, the deepest baking degree, the beans are black and bright, the surface is oozing, the bitterness is very strong. At this stage, coffee beans have been severely carbonized, and it is difficult to distinguish the taste of one kind of coffee bean from another. Used for Italian steam pressurized coffee.

III. Baking characteristics all over the world

Cities all over the world have their own preference for baking. In Tokyo, micro-deep medium baking is more popular, but slowly also tends to deep baking. In the West, deep baking has been popular since ancient times. New York, as its name suggests, generally prefers urban baking, but because it is inhabited by different races, it sells coffee beans with different roasting levels. Vienna prefers deep baking. The French prefer French baking, while Italians often use Italian baking.

However, in recent years, Italian baking (the most commonly used deep roasting in Brazil and Italy) has been widely used in Europe and the United States, and the coffee made by steam pressurizer is still popular. Deep roasting of Ethiopian coffee beans would be a waste. Because that would lose the unique characteristics of this kind of coffee. Black roasting of Yauco and Kona coffee beans is also bad, because you will lose the classical flavor you pursue when you buy it.

When some coffee beans are roasted black, new and interesting qualities will be derived. Mexican coffee beans produce an interesting sweetness when roasted in black. Guatemala Antigua coffee beans seem to retain their sour and fruity flavor when they are deeply roasted, which is difficult for other coffees. Sumatran coffee beans are usually full-grained, but below medium acidity, lose acidity when roasted deeper, and easily turn into sugar paste. Generally speaking, the darker the baking, the lower the quality. Deeper roasting means losing most of the flavor of the coffee beans.

Roast coffee beans at home

The hardest part of coffee-related activities is baking coffee beans at home. When making high-quality coffee, whether the beans are fresh or not is very important. The easiest way is to bake coffee beans in the oven. The biggest advantage of this is that it adjusts the temperature so that the smell of roasted coffee does not pervade your home. Heat the oven to 230 degrees in advance. Remember to keep the coffee beans well ventilated and don't spread the beans too thick. After baking for about 10 minutes, observe the change of color. Pay attention to the crackling sound of coffee beans and check the color all the time. When the coffee beans are only a little lighter than you want, remove them from the oven to cool. The residual heat will heat the coffee beans for 2 more minutes. Home baking stoves can also be used, but the best is the traditional flat pan or popcorn (popcorn) model. Use a handle to manipulate two vertical pieces of metal inside the machine that rotate the coffee beans during roasting. This can be bought in second-hand stores or good kitchen utensils stores, where you can also buy inexpensive oven thermometers. After the coffee is roasted, take them out of the grill and put them in a heat-resistant bowl. Put the bowl by the window or outdoors.