Coffee grinding the most critical focus is the following:
First, the grinding degree should be uniform; Second, as little as possible to produce friction heat; Third, try to avoid fine powder; Fourth, select the extraction method for grinding.

(1) grinding to be uniform
Uneven degree of grinding on the deterioration of the coffee taste is deadly, coffee extraction law is “the smaller the grinding degree of bitterness, the weaker the more sour, grinding more bitter weaker the more sour.”

(2) as little as possible to generate friction heat
Grinding machine will produce heat at working. The friction heat will significantly damage the aroma and flavor of coffee. The heat generated by the friction will significantly damage the aroma and flavor of coffee, and the faster the rotational speed the greater the heat.

(3) try to avoid fine powder
The influence of fine powder on the extraction of coffee is even greater than the heat of friction. The high temperature and static electricity generated by the grindstones can cause the fine powder to adhere to the inside of the grinder and the passage. At the time of working, there are residual powder after oxidation rancidity In the next grinding will be mixed with new coffee powder, resulting in deterioration of taste, not only the coffee liquid turbidity, but also bring unpleasant bitterness and astringent taste and even smell.

(4) Select the appropriate grinding method of extraction
Brewing method VS particle thickness of the match
1, coarse grinding: the size of such as crude sugar, suitable for filter press coffee.
2, in the mill: grit-like, the size between on coarse sugar and sugar the more suitable for drip-type boiling method.
3, fine grinding: the size of such as fine sugar, more suitable for distillation coffee pot, electric coffee pot, Mocha pot.
4, very fine grinding：the size between of salt and flour between the more suitable Espresso, because the home grinder can not grind this texture, generally have to buy ready-made grinding powder, so if you want to enjoy Espresso at home, the best drink to Large, in order to drink fresh coffee.