Where does the bitterness in coffee come from?

Many people will think that caffeine is the source of coffee bitterness, but in fact caffeine accounts for only 1/10 of the bitterness, so where does the remaining 90% come from?

1. Brown pigment

Brown pigment is divided according to the size of the molecule, and the bigger the molecule, the stronger the bitterness. In the process of baking, deep baking will increase the brown pigment, and the brown pigment with larger molecules will also increase. So when drinking deep-baked coffee, you will find that it has a strong bitter taste. Arabica and Congo coffee beans have different bitterness and taste, which is due to the amount and molecular size of brown pigment. The content of oligosaccharides in Congo is relatively low, and caramelization will not occur, so it is easy to produce brown pigments with large molecules, and it is easy to produce bitterness even if it is baked lightly.

2. Amino acids and proteins

Cyclic diaminic acid is produced during the heating of amino acid and protein, which is a substance produced by the combination of two amino acids. The intensity of bitterness varies with the way of combination. In addition to coffee, cocoa, dark beer and other substances are also produced by it.

However, the bitterness can be controlled by changing the type of coffee beans, the way of baking, the degree of baking and the method of extraction. Acid, etc.