The strength and skill of pressing coffee powder has a great influence on the quality of coffee.

(Ⅵ)

Chapter 6 Pump Pressure

The most mysterious part of brewing coffee is that the roasted beans not only contain fragrant flavor, but also contain other substances that taste worse. At the beginning of this century, Italians came to the correct conclusion:

Pressurizing water can separate these two substances more efficiently.

The oil is emulsified by pressure and extracted to form crema, a reddish brown foam. Crema contains delicious substances that are refreshing. What is the optimal pressure? It is generally believed that the pressure of boiling espresso should be between 8.2 and 9 atmospheres. I set it at 8.2 atmospheres.

steady pump pressure

The water pressure in our shop is very unstable, high in the morning and low in the afternoon. Sometimes there will be a momentary surge, and even when the dishwasher in the back is flooded, it will affect the espresso machine in the front bar.

As soon as the inlet pressure changes, espresso's rotary pump also changes. In order to solve this problem, we installed a 3 gallon stainless steel tank in front of the water inlet of the espresso machine, equipped with an automatic water inlet device (including float switch, solenoid valve, adapter), which can maintain the pressure of the water inlet at 1 atmosphere.

potential trouble

Care should be taken not to leak gas from these newly added pipe fittings. Pump inlet can not be empty without water pumping. Otherwise, the pump of the espresso machine, which was originally used to pump water, will suck in air and will not work, and the pressure will not come up.

Espresso Coffee: Professional Techniques 1996 Edition

Source: Bolan Coffee College