Roasting Reaction Change--Coffee Roasting Caramelization

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Raw coffee beans do not contain the special aroma of coffee, so they are not eaten directly and need to be roasted before a large number of volatile aroma substances are produced.

After roasting, the main volatile aroma components of raw coffee beans are more than 660 by analysis, which is the food with the largest variety of volatile aroma components in all foods and beverages. The aromas produced in the baking process, such as hazel, cream and caramel, or with grass, smoking, burning, spice and bitterness, are often volatile substances. In addition, the difference of roasting degree will also affect the flavor characteristics of coffee.

Caramelization is a link that has the greatest impact on the flavor of coffee. After baking for six to seven minutes, raw beans absorb a lot of heat and start the pyrolysis reaction, resulting in the first explosive sound. Some sugars are converted into carbon dioxide, and water continues to evaporate. New aromatic components gradually develop into 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.