What does cleanliness in coffee roasting mean?

In coffee roasting classes, people keep talking about how to find "clean" roasting, which is actually the most direct description of the preparation of different drinks and the criteria for judging the coffee beans used in their products. therefore, some people always ask, what does "clean" roasting mean?

Today, I hope to explain it in a more specific and visual way through this article, because when it comes to coffee, we must be able to understand the importance of "cleanliness" in different areas of the coffee industry.

The so-called "clean" roasting refers to the relatively complete retention of coffee flavor and aroma based on the origin, variety and processing characteristics of coffee beans.

It is well known that different degrees of roasting produce different chemicals, which in turn make the same batch of coffee beans show different flavors; chemical elements at different stages are produced in different temperature ranges.

This means that the more we understand the internal structure and chemical composition of raw beans, the more we can control the formation of flavor.

Generally speaking, if the temperature is not enough, the organic chemicals used to transform flavor and aroma cannot be fully decomposed, then chlorogenic acid will be maintained at a high level, that is, the astringency of coffee, the taste of grass or milk, and the sour taste.

If the roaster is overheated, the risk of forming a dry distillation chemical flavor will be increased, that is, rubber, smoky, bitter, spicy and charcoal flavor will be more prominent.

Sometimes, rapid baking at high temperature will result in the result that the outer surface of the bean is scorched but the central part is underbaked, in which case the two problems will occur at the same time.

If you can ensure strict implementation of raw bean sample baking standards, and have mastered mature cup testing techniques to make adequate preparations for "clean" baking, then the next thing you need to do is, try to balance or control the variables of all baking tools: speed, firepower, wind speed, weight, and use the right temperature at the right time according to different raw bean varieties and handling methods.