Getting to Know Your Espresso Machine

Knowing how your espresso machine works is very important when purchasing an espresso machine. While every espresso machine is unique in its own way, all espresso machines are similar in how they essentially work. If you understand how your machine works, you can fix problems when they occur, as well as improve your barista qualities and make better coffee.

All espresso machines are composed of several different parts. These include the water tank or reservoir, the water pump, the heating chamber, and the grouper part. While some machines may have more elements to these, such as dual water tanks, or may lack some, such as the water pump, all are basic variations on this model.

The process to make espresso starts in the reservoir. Here water is stored before use. The water pump draws the water up and pressurizes it to about 22 atmospheres. Then it pushes the pressurized water into the heating chamber where it is heated to the exact temperature required to extract the best flavor from the coffee. Some older machines or cheaper models may not have a water pump, and will instead heat the water right in the reservoir, building pressure with the steam.

From here, the pressurized water is forced through the grouper head. The grouper head is the basket and metal sieve in which the espresso grounds sit. By forcing the pressurized water through the grouper head full of espresso, the heat and pressure forces the flavors and natural sugars in the beans out. This becomes the shot.

These components all work together to pull a shot. Usually the heating chamber or the reservoir will also be able to direct steam to a steaming wand. Usually the flow of the steam is controlled by a simple valve that either directs the steam to the grouper or the wand.

By understanding how all these parts work together you can, for example, understand that if all your shots keep tasting burnt, your machine may need to be serviced to make sure that the heating chamber isn’t heating the water too high. Understanding how your espresso machine makes espresso will also help you recognize problems before serious damage is done, saving you money.