The 8 Stages of Roasting Coffee Beans: A Complete Guide

The 8 Stages of Roasting Coffee Beans: A Complete Guide

Roasting is the process of heating raw coffee beans to a certain temperature to cause chemical changes that produce aroma and flavor. This process can be divided into eight stages, each with its own specific temperature and time requirements. In this article, we will take a detailed look at each stage and how to master them.

1. Preheating

Preheating is to preheat the coffee beans to a lower temperature (about 100°C) to remove surface moisture and reduce the acid content. This step usually lasts 1-2 minutes.

2. Drying

In the drying stage, the temperature is gradually raised to about 150°C and maintained for 15-20 minutes. At this time, the water inside the coffee beans begins to evaporate and the color changes from yellow to brown.

3. Yellowing

When reaching about 180°C, the coffee beans will take on a distinct yellow color and emit a grain-like aroma. This stage usually lasts 2-3 minutes.

4. First Crack

The first burst is one of the most important stages in the roasting process. When the temperature reaches about 200°C, the coffee beans will begin to expand rapidly and make a sound similar to popcorn popping. At this time, the carbon dioxide inside the coffee beans begins to be released, and a rich aroma and flavor are also produced.

5. Medium Roast

In the medium roasting stage, the temperature gradually rises to about 220-230°C and is maintained for 10-15 minutes. At this point, the surface of the coffee beans becomes smooth and shiny, and the color changes from light brown to dark brown. This is the traditional roasting degree that most people prefer.

6. Second Crack

The second burst is a sign of entering the deep roasting stage. When the temperature reaches about 240°C, the coffee beans will quickly dehydrate again and the fat will decompose to produce a more shiny surface. At this time, there will also be a sound similar to popcorn popping, but it is lighter than the first burst.

7. Dark Roast

In the deep roasting stage, the temperature gradually rises to about 250-260°C and is maintained for 5-10 minutes. At this point, the surface of the coffee beans becomes very shiny and the color changes from dark brown to black. This degree of roasting is usually used to make strong Italian coffee.

8. Charred

If the coffee beans continue to be heated above 260°C, they will enter the coalification stage, where a noticeable burnt black color will appear on the surface of the coffee beans, and the flavor will become bitter and unacceptable.

Understanding the temperature and time requirements for each stage is essential to mastering the roasting process. Choosing the right roasting degree based on your taste preferences and desired flavor profile is the key to making quality coffee.