・ What is roasting?
Roasting is the process of roasting coffee in the form of raw beans. Roasting is an important process that determines the deliciousness of coffee, and its taste changes greatly depending on the heating time and how the heat is applied.
・ Changes in coffee beans caused by roasting
Roasting coffee beans can be divided into three types, light roasting, medium roasting, and deep roasting, depending on the time of cooking. The green beans gradually turn brown as they are roasted, and then turn black. At this time, coffee beans undergo three chemical reactions.
One is called the Maillard reaction, and the substance that is the source of umami and aroma is produced by this reaction. This reaction is the reason why people feel that they have a nice aroma, fragrance and deliciousness when they bake and eat food.
The second is caramelization, a reaction that produces substances with a sweet scent and a unique bitter taste. Products that utilize this reaction include bekko candy and caramel.
And the third thing that is happening is the reaction of decomposition. Some of the ingredients contained in raw beans are decomposed into sour substances by heating.
The shallower the roasting, the stronger the acidity produced by the decomposition, but the longer the roasting, the more aroma due to the Maillard reaction and the bitterness due to caramelization. In this way, it is possible to create various coffee flavors and characteristics by using the reaction.