It is a fact that the coffee ground by a small electric bean grinder (such as a small pulverizer) is uneven. Therefore, it is suggested that when grinding beans, you should shake them up and down like drawing lots in the temple. The goal is to make the coffee beans rotate as evenly as possible, but this is just as much as possible. But the biggest advantage of this machine is that it can grind quickly and keep the aroma as much as possible. However, the grinding speed of hand mill is slow, and the aroma will evaporate a lot. If we must compare the advantages and disadvantages of these two bean shops, we can only say that radish and cabbage have their own love. The difference is not too big.
The degree of grinding is closely related to the extraction time, which directly affects the taste. For example, the coffee ground by hand mill or small pulverizer has a large proportion of roughness, so if you want to get a mellow taste, you must increase the soaking time. On the contrary, if the proportion of fine coffee is large, and you want to pursue bright fruit acid and low bitter coffee, then you must shorten the soaking time.
For the same kind of coffee beans, under the same water temperature and water quantity, the fine ground coffee has higher mellowness and brighter acidity.