Pay attention to the uniformity, fine powder quantity and calorific value of the bean grinder are helpful to the final extraction of coffee.

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Use a bean grinder to help extract coffee

Evenness degree

Coarser coffee particles are more likely to be underextracted, while finer particles are overextracted in advance, so the coffee powder with a larger span of grinding thickness can taste more turbid and irritating smells. When the coffee powder with the same size and similar shape is used for extraction, the taste becomes brighter and stronger, and the performance of flavor characteristics is clearer and consistent.

Fine powder content

Coffee powder close to flour can easily be overextracted or even dissolved in water, thus affecting the extraction taste of coffee. The more fine powder, the more easily coffee is over-extracted, and the more bitter the taste is, the more mixed it is. When making espresso, the fine powder will first be washed out by the water and into the cup. If extracted properly, the thick oil will hold up the fine powder, and the fine powder will float on the surface of the oil, forming a beautiful "tiger spot". But "tiger spot" does not represent the taste of espresso. The production of fine powder can be reduced by choosing a better bean grinder or using a sieve. But if there is no fine powder at all, the brewed coffee will also lack a sense of hierarchy.

Calorific value

The grinding plate of any bean grinder will generate heat in the grinding process, and the heating of coffee powder will accelerate the oxidation process and accelerate the volatilization of aroma, resulting in the weakening of coffee flavor after brewing. The calorific value of the cutter head depends on the size of the grinding plate, the material used, the structure of the knife, the fineness of grinding, the speed of the motor, the hardness and texture of coffee beans and many other factors.

Static electricity

Generally speaking, the finer the grinding, the faster the grinding machine, the stronger the static electricity; the internal material is plastic, and the lower powder mouth does not use the bean grinder designed to reduce static electricity, so the static electricity is stronger; the coffee beans with rich oil and deep roasting are ground, the static electricity is stronger. When the Italian bean mill is grinding, it often appears that the fine powder agglomerates, which affects the density after the cloth powder, resulting in uneven extraction, while the iron absorber at the outlet of the single bean mill absorbs silver skin and fine powder through static electricity to help reduce the taste and miscellaneous smell of excessive extraction.

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