Roasting of coffee beans: the relationship between roasting degree and acidity the difference between shallow baking and deep roasting

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Guide reading

The taste of coffee comes from various factors, such as the planting conditions of the place of origin, the variety of coffee, the way of treatment and so on. Finally, the roaster bakes the raw beans of coffee into ripe beans, and the flavor and degree of roasting will affect the final taste of coffee.

Roasting can be said to be one of the most important factors affecting the taste of coffee, and the same bean will form a different flavor experience by roasting to different depths. How does roasting affect coffee? Does the degree of roasting affect the acidity of coffee?

First

How do you divide the degree of baking?

In the coffee roasting process, coffee beans will experience dehydration, yellowing and then to one explosion, one explosion density, if you continue to roast, there will be a second explosion, a second explosion density, and so on. Looking through different materials, you will find different expressions about the degree of baking. at this time, we introduce the concept of an Eiger value.

The American Fine Coffee Association SCAA uses infrared caramelization tester technology (Agtron) to measure the color of coffee beans to reflect the roasting degree of coffee, and divides the color from light to deep into eight equal parts into eight standard color blocks, which can be used by the coffee industry as the determination of roasting.

Agtron color value # 95: light baking (Light Roast)

Time to drop beans: the density of explosion is coming to an end.

Agtron color value # 85: cinnamon baking (Cinnamon Roast)

Time to drop beans: before and after the end of the explosion

Agtron color value # 75: medium baking (Medium Roast)

Time to drop beans: after the explosion is over

Agtron color value # 65: deep baking (High Roast)

The time of dropping beans: the quiet period between the first explosion and the second explosion

Agtron color value # 55: urban baking (City Roast)

Time to drop beans: the second explosion begins.

Agtron color value # 45: city-wide baking (Full City Roast)

Time to drop beans: before the second explosion is dense.

Agtron color value # 35: French baking (French Roast)

Time to drop beans: when the second explosion is dense

Agtron color value # 25: Italian baking (Itatian Roast)

Time to drop the bean: the oil begins to seep out of the bean surface

Although there are still loopholes in this set of standards, we have to admit that the Eiger value is still a valuable method to detect the degree of baking.

With this set of Eiger numbers, we can see how coffee performs at different levels of roasting. Will the acidity of coffee vary with different degrees of roasting?

Effect of roasting degree on acidity of Coffee

Qianjie Coffee measured the Eiger-shaped values of several coffee beans with different roasting degrees, and then tested the cups. The front street sampled Ethiopian water-washed fruit Tintin cooperative, Honduran sherry bucket coffee, washed blue mountain coffee and golden manning coffee.

Qianjie Coffee measured the Eiger values of four coffee beans through the Eiger value tester, including 80.8 for washed Yega Shirley, 78 for Honduran Shirley barrels, 65.4 for Blue Mountain Coffee and 61 for Golden Manning.

Then four coffee beans were tested respectively. Qianjie Coffee believes that the cup test belongs to the extraction method with the least human factors, which can best reflect the taste of the coffee bean itself. By sipping atomized coffee liquid, we can better judge the factors of coffee. Finally, we found that the order of acidity from high to low was washed Yega Sherfield > Shirley barrel coffee beans > washed Blue Mountain Coffee > Golden Manning.

So it is not difficult to know that the degree of roasting of coffee will affect the acidity of coffee to a certain extent, the deeper the roasting degree, the less acidity of coffee. This is because bitter substances, such as chlorogenic acid lactone and phenyllindane, are gradually produced during the baking process, and these products become more and more as they are baked, especially after the second explosion.

For many guests who don't like acidity, Qianjie Coffee always recommends deep-roasted Mantenin coffee, while guests who like sour fruit are more likely to recommend lighter roasted beans, such as washed Yega Chuefei or Kenya.

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