Principles of coffee grinding

1. The grinding degree suitable for brewing method should be selected;

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

3. The powder after grinding should be uniform;

4. Grind before brewing.

No matter what kind of grinding machine is used, it will certainly generate heat by friction during 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 coffee beans are ground, the cell wall will completely disintegrate, the area in contact with air will increase a lot, the oxidation and deterioration speed will become faster, and coffee will lose flavor within 30 seconds to 2 minutes. Therefore, it is recommended not to buy coffee powder, it is best to buy coffee beans, grind before drinking, grind well should be brewed quickly.

Before the invention of the bean grinder, humans ground coffee beans using stone pestles and bowls. A doctor abroad once experimented with this ancient tool and compared it with a modern bean grinder. It is said that the coffee powder ground by the pestle and stone bowl can best soak out the mellow flavor.

Logically, the pestle should crack the beans naturally on impact without damaging the cell walls and retaining the good stuff of coffee. However, in modern life, it is almost impossible to use pestle and stone bowl to grind coffee beans, so it is particularly important to choose a good grinder.