Fine coffee knowledge coffee bean grinding terminology

Tannic acid: after extraction, tannin will turn into a yellowish powder, which can easily blend into water. After boiling, it will decompose and produce pyrosylic acid, which will make the coffee taste worse. If the coffee is soaked and left for several hours, the color of the coffee will become stronger than when it was just soaked. And it is also less tasty, so there is the saying that "it is best to drink it as soon as possible."

Caffeine: caffeine is the most eye-catching of all the ingredients in coffee. It belongs to a kind of phytoxanthine (animal muscle component). It has the same properties as theophylline contained in cocoa, green tea contains the same theophylline, and the percentage of reduction after baking is very small. Caffeine has a very extensive effect. It will affect various parts of the human brain, heart, blood vessels, gastrointestinal tract, muscles and kidneys. The right amount of caffeine will stimulate the cerebral cortex, promote sensory judgment, memory and emotional activity, and make the myocardial machinery more active. Vasodilation enhances blood circulation and improves metabolic function. Caffeine can also reduce muscle fatigue and promote digestive juice secretion. In addition to this, because it also promotes the kidney function to help the body expel excess sodium ions (chemicals that hinder the metabolism of water molecules), caffeine will not accumulate in the body like other narcotic and excitant substances (narcotic drugs, paint solvents, stimulants, etc.) and will be excreted in about two hours. The biggest bitterness of ─ in coffee flavor is caused by caffeine.

Fat: the fat contained in coffee plays a very important role in flavor. It is found that there are many kinds of fat in coffee, the most important of which are acidic fat and volatile fat. Acidic fat means that there is acid in fat, and its strength varies with different types of coffee, and volatile fat is the main source of coffee aroma. Once the fat contained in roasted coffee beans comes into contact with the air, chemical changes may occur and the taste and flavor will become worse.

Protein: the main source of calorie is protein, and like dripping coffee, most of the protein will not dissolve out, so no matter how much coffee you drink, the nutrition you get is limited, which is why coffee will become a sacred food for dieters. The task of grinding roasted coffee beans into powder is called crushing.