How well do you want to grind the coffee beans? How to choose rough and fine grinding?

An important step before brewing coffee beans is to put them into a grinder for grinding, and the consensus in the coffee industry is that evenly ground coffee beans are relatively easy to brew well. But some coffee lovers have doubts about the grinding size of coffee beans during the DIY process.

Coffee beans become coffee powder, in fact, from a solid is cut into countless individuals, each cut, the coffee particle surface area will increase, if a coffee bean is completely cut under ideal circumstances, its surface area can reach the size of a standard basketball court. There are many cuts, and the soluble substances in coffee particles are more easily extracted by water, so there are only 30% of the soluble matter in a coffee bean, while 5% of the 30% is bad flavor. So our goal is to extract about 25% of the aromatic substances.

Then the choice of the degree of grinding is solved in theory. If you want to extract more substances, grind the coffee beans as fine as possible, and if you want to extract fewer substances, use relatively coarse grinding, and in order to extract the aromatic substances as much as possible, the American Fine Coffee Association recommends that the degree of grinding of coffee powder on the sieve of 20mm is 70%. If it is more intuitive, you can use the fine granulated sugar at home as a reference. Grind the coffee powder to the size of fine sugar, which basically meets the requirements.