What Happens During Coffee Roasting: The metabolic process of coffee beans

1. The purpose of roasting coffee

Coffee cannot be eaten immediately like other types, it can only be brewed for drinking. Therefore, to be able to get all the essences in the coffee beans, one must grind them into powder.

However, the aroma and aftertaste of coffee would not be complete without the roasting process.

Because, under the heat effect of roasting, it will change the chemical composition of substances in coffee beans, such as caffeine, lipid, protein. From there, create a unique aroma of coffee beans.

The purpose of roasting is to maximize the flavor of the instant coffee chemicals.

The purpose of roasting is to maximize the flavor of the instant coffee chemicals. Internet: Image

The purpose of roasting is to maximize the flavor of the instant coffee chemicals. The soluble solids make up the taste of coffee; while the volatile active substances have the aroma and oils that make up the aroma of coffee. Soluble solids, oils and cellulose (cellulose) fragments of the grain create a strong (body) flavor.

In addition, roasting makes coffee processing easier, eliminates most of the water inside the grain, leaving only the fat and wax.

2. The process of changing the quality of roasted coffee beans

Roasting of coffee will be started from the time the temperature reaches 100 degrees C until ending at 240 degrees C.

During this heating process, the ingredients in coffee will begin to transform:

When it reaches 100 degrees Celsius>

The amount of water inside will begin to evaporate, causing the coffee core to shrink.

From 100 – 150 degrees Celsius

As the water continued to disappear, the coffee began to change color to pale yellow. The shrinking process continues and with it the aroma begins to rise.

From 150 – 180 degrees Celsius

If kept at 150 degrees Celsius, the coffee core will turn from light yellow to light brown. At this time, it needs to be heated to 180 degrees Celsius to make the coffee smell better. The shrinking process ends, instead, the expansion of the volume due to the internal components begins to disintegrate.

variation in color of coffee beans when roasting

Variation in color of coffee beans when roasting. Image: internet

From 180 – 200 degrees Celsius

During the heating process from 180 to 200 degrees Celsius, the coffee bean has swelled to its utmost, the aroma was sweet; the internal components were easily brought to grind. However, at this time, the finished product will not have the best quality and will not have sour taste.

From 200 – 210 degrees Celsius

Coffee beans begin to expand to the point of explosion, smoke begins to rise to create a fragrant aroma and spread further.

From 210 – 230 degrees Celsius

Coffee beans continue to swell due to the release of more carbon dioxide and explosions.

From 230 – 240 degrees Celsius

The seeds will now have a dark brown color, a strong aroma, and the internal ingredients will also be modified to achieve the best flavor. This is the best time to puree and start mixing.