Espresso requires the finest grinding compared to other brewing methods (except Turkish coffee), which means that to get the same amount of coffee, espresso requires a much heavier grind than filter coffee. When specialty coffee shops sell more espresso than filter coffee, the load on the grinder will be heavy, so an espresso grinder for espresso is more needed. (If you want to make more than 60 cups of latte in one hour, for example, the amount of powder in one cup is 16 grams, which is 960 grams in one hour, or about one kilogram of coffee powder, the continuous operation stability of the burr is very important.)
Espresso grinders can be divided into two types: conical knife grinders and flat knife grinders. The two are like Ford versus Chevrolet, both have their own fans.
Regardless of whether you choose a conical or flat-knife grinder, in fact all espresso grinders have two difficulties to overcome: temperature fluctuations and grinding residual powder.
Friction generates heat, and when grinding coffee beans for espresso, the coffee beans need to be ground extremely fine and are constantly rubbed. No matter how busy the barista is, any barista knows that the fluctuations in temperature caused by the espresso grinder will seriously damage the espresso. parameters, during peak operating hours in the morning, the brewing time will speed up as the temperature of the grinder increases.
Another headache is residual powder. Some coffee powder will remain between the grooves and the cutter disc of the grinder. This means that whenever you grind coffee, it will be accompanied by residual powder from some previous coffee beans. Even if you grind two or three beans, you still can’t be completely sure that the previously ground coffee is not in the machine. Therefore, the ground coffee will have different particle sizes, resulting in uneven extraction and increased chances of clogging.