Professional coffee roasting knowledge coffee grinding process

(1) the principle of grinding

Generally speaking, a good grinding method should include the following four basic principles:

1. The degree of grinding suitable for brewing and cooking should be selected.

2. The temperature of cattle produced during grinding should be low.

3. The powder particles after grinding should be uniform.

4. Grind before cooking.

No matter what kind of grinder is used, it is bound to generate heat by friction in operation. Most of the fine substances are highly volatile, and the heat of grinding will increase the speed of volatilization, so that the aroma of coffee is lost in the air. After the coffee bean is ground, the cell wall will completely disintegrate, the area of contact with air will increase a lot, the rate of oxidation and deterioration will become faster, and the coffee will lose its flavor within 30 seconds to 2 minutes. Therefore, it is recommended not to buy coffee powder, it is best to buy coffee beans, grinding before drinking, grinding should be brewed as soon as possible.

Before the invention of the bean grinder, people used stone pestles and bowls to grind coffee beans. A doctor abroad once experimented with this ancient tool and compared it with a modern bean grinder. It is said that the coffee powder made from pestles and stone bowls is the most mellow.

According to logical reasoning, the pestle cracked the coffee bean naturally by impact, which should not destroy the cell wall and retain the excellent substance of coffee. However, in modern life, it is almost impossible for people to use pestles and stone bowls to grind coffee beans, so it is particularly important to choose a good bean grinder.

(2) the method of grinding

According to the size of coffee beans, the grinding methods can be divided into rough grinding, medium grinding and fine grinding. Use the appropriate grinding method according to the coffee utensils. There is also medium fine grinding or finer and finer grinding than fine grinding (powdered coffee powder).

1. Fine grind: the particles are fine, the same size as sugar.

2. Medium grind: the particles are the same size as the mixture of granulated sugar and crude sugar.

3. Rental grinding (Regular grind): the particles are thick, as big as coarse sugar.

(3) the secret of grinding

1. The grinding tool for coffee beans is a bean grinder. There are three kinds of bean grinders:

(1) Manual rotary bean grinder for household use. It is suitable for leisure people with small demand, large particles and plenty of time.

(2) Electric bean grinder for household use. Can be ground into a variety of particle size coffee powder, can be ground out of 6 people at a time.

(3) Professional use of electric bean grinder. For commercial use, about a pound of coffee powder can be ground at a time.

2. The following two points should be paid most attention to when grinding coffee beans:

(1) reduce the heat of research. Grinding heat will cause the aroma of coffee to dissipate early.

(2) the particle size is uniform. Uneven particle size will lead to uncontrollable brewing time.

So if you use a family-style manual bean grinder, you should rotate gently so that it does not produce friction heat as much as possible. To sum up, if you consider the quality, quantity, time and convenience of grinding beans, the use of electric bean grinders for home use will be the best choice.