Coffee bean processing method Roasting technology skills: Coffee bean roasting degree introduction

The taste of coffee mainly depends on roasting, generally shallow roasting will have a brighter sour taste, deeper roasting will have a stronger bitter taste, this is the basic rule. The depth of baking mainly depends on the characteristics of raw beans, personal preferences and other factors, the most important is the balance between bitter taste and sour taste.

Roasting is roughly divided into light (LIGHT), medium (MEDIUM), deep (DARK) and very deep (VERY DARK) roasting, light roasted coffee beans: will have a strong smell, very crisp, high acidity is the main flavor and light mellow. Medium-roasted coffee beans: have a strong mellow, but also retain most of the acidity. Deep-roasted coffee beans: there are traces of grease on the surface, and the acidity is replaced by a slight bitterness, resulting in a pungent taste. Very dark roasted coffee beans: the color is black, because the oil to penetrate to the surface, with a bitter taste of carbon ash, mellow significantly reduced. 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.

The baking degree is nothing more than shallow culture, medium baking and deep baking, but what about the standard? So far, there is no consensus in the coffee industry. Each company plays its own tune, and the American eight-stage baking degree classification is adopted at most in the industry, and the baking degree is determined by baking temperature and time.

American grading baking degree:

1. Shallow baking (Light Roast) L value = 30.2

The lightest roasting degree of all roasting stages, the surface of the coffee beans is a light cinnamon color, its taste and aroma are not enough, generally used for testing, rarely used to taste. In terms of baking time, it is close to the so-called "first explosion" (note: it refers to the first burst caused by the heated volume expansion of raw beans during baking)

Shallow baking (Light Roast)

two。 Cinnamon baking (Cinnamon Roast) L value = 27.3

The appearance shows cinnamon, the smell of green has been removed, the fragrance is OK, the acidity is strong, the taste of coffee is light, and there is less selling on the market. In terms of time, it is about the middle of the "explosion".

Cinnamon baking (Cinnamon Roast)

3. Medium baking (Medium Roast) L value = 24.2

The appearance is brown, in addition to the sour taste, the bitter taste also appears, the taste is good. At this time, the acid is heavier than bitter, moderate mellow, also known as American baking. In terms of baking time, it is nearing the end of "explosion".

Medium baking (Medium Roast)

4. Deep baking (High Roast) L value = 21.5

It belongs to moderate micro-deep baking, the surface has appeared a little thick brown, and the bitterness has become stronger. Coffee tastes sour and bitter, with good aroma and flavor, and is the most popular way of baking beans on the market. In terms of baking time, the "explosion" is over, when the coffee beans are wrinkled and the aroma changes.

Deep baking (High Roast)

5. Urban baking (City Roast) L = 18.5L

The appearance of coffee brown, the most standard degree of roasting, bitter and sour taste balance, so that the coffee has a multi-layered feel, so that Americans who originally prefer medium roasting change their taste and like it. In terms of baking time, it is close to the so-called "second explosion" (note: it means that the raw bean continues to lose a lot of water after heating for the first time, and the volume expands rapidly to produce the second burst.)

Urban Bakery (City Roast)

6. Deep city baking (Full-City Roast) L = 16.8L

The appearance shows dark brown, the color becomes quite dark, the surface appears oily, bitterness is stronger than sour taste, it is suitable for coffee beans with strong characteristics, such as Mantenin, Hawaiian Cona and so on. In terms of baking time, the "second explosion" is just over.

Deep urban baking (Full-City Roast)

7. French baking (French Roast) L value = 15.5

Is a deep baking, the appearance is still black with a trace of brown, strong brown with black, sour taste can not be felt, in Europe, especially in France is the most popular, because the fat has infiltrated to the surface, with a unique flavor, very suitable for iced coffee, Viennese coffee.

French baking (French Roast)

8. Italian baking (Italian Roast) L value = 14.2l

The coffee beans are roasted to an all-black, oily surface, close to coking, with only bitter taste, simple taste and sometimes smoky taste. It is suitable for highland coffee beans with thick pulp and strong sour taste. Although it is called Italian style, Italian espresso Espresso has been roasted in more cities or deep cities.

From a professional point of view, the degree of baking is expressed as an L value. The L value is black = 0 white = 100, and the bright measure is measured by a colorimeter. As the baking time increases, the color of the coffee bean becomes darker, and the L value is closer to 0.

Since the concept of boutique coffee is popular, it is now distinguished by the eight-stage baking degree SCAA Agtron method developed by the American Fine Coffee Association (SCAA) with a caramel analyzer.

Distinguishing baking degree by SCAA Agtron method to judge baking degree SCAA tonal plate

Of course, this method can only be used as a reference, because the same baking degree does not mean that the cup test results must be the same. The point is that the baking rhythm is the main factor that determines the flavor of coffee, and bean color is just a reference. Only by mastering the similar baking rhythm of the same beans can we ensure the consistency of the flavor of each batch of coffee and achieve the same quality.

Source:

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