Knowledge of Fine Coffee A brief discussion on why coffee beans are roasted

The raw coffee beans for export are not the dark brown beans we often see in cafes with a luster of vegetable oil and a burst of coffee-scented beans. Coffee beans can only be roasted to become coffee beans for grinding and drinking. Of course, this is just a strange modern way, because in the early days, Ethiopians used the fruits of coffee to make wine. Or brew coffee fruit to make drinks. Nowadays, even if someone wants to try this ancient way of drinking coffee, ordinary people can't find fresh coffee fruit in North America and Europe, which consume a lot of coffee. Roasting coffee beans, then grinding and brewing them has become a classic process for people to enjoy coffee.

Baking is the beginning of this process. 80% of the taste of coffee is determined by baking. It can be seen that roasting is very important in coffee production.

Why roast coffee beans? This is because roasting gives off aroma of coffee and makes different kinds of coffee give out different flavors. Without this process, the unique taste of coffee will be greatly reduced. Roasting causes coffee to produce coffee oil, which gives coffee beans a strong aroma. The most outstanding feature of this fragrance is that it is volatile and soluble in water. Therefore, people can not only ask about the mellow smell of coffee beans, but also pour it into the cup and taste it carefully.

Baking, as the name implies, is to provide heat to coffee beans, causing a series of chemical changes inside. First of all, the starch in raw beans will be converted into sugars and acids because of high temperature, while substances such as cellulose will be carbonized differently. Water and carbon dioxide evaporate, while proteins are converted into enzymes, which combine with the rest of the fat to form an oil film on the surface of coffee beans. Coffee beans swell when roasted, a bit like popcorn, and interestingly, coffee crackles during roasting, just like we use microwave popcorn. But because the skin on the surface of coffee beans is very tough, we usually don't see coffee beans crack like popcorn.

We often see that roasted coffee beans have different shades of color, on the one hand, this may be due to different types of individual coffee beans, and on the other hand, the main reason for this color difference is the different degree of roasting. In the most popular language, the degree of baking can be interpreted as the heat of baking. Take the most classic example of carbonated coffee, a French roasted coffee that is highly carbonized, dark brown and carbon black due to its deep roasting (either because of the high temperature during baking, or because of the long baking time, or both, depending on the situation). It is generally believed that carbonized coffee tastes bitter, which comes not only from caffeine but also from carbonized coffee beans.