There are several factors that go into making a high quality coffee. The taste result in our cup can be influenced by the type of coffee we have chosen and the way it is prepared, as well as by the capabilities of the equipment we have and the skill of the barista. But a constant factor that affects the quality of the coffee although we often tend to overlook, is the cleanliness of the equipment.
Even a high-quality coffee cannot compensate for the low-tasting result offered by a dirty machine. Coffee beans contain essential oils, which of course give us the rich crema and wonderful flavor that top off our espresso, but at the same time they can change the taste of the coffee, adding a bitterness. The coffee oils are deposited and accumulate in various parts of the machine such as the shutter, the filter, the head of the group, etc. Over time these oils form a film on the filter and shutter (see picture). The process of removing oils and coffee grounds is called “backflushing”.
In addition, the accumulation of water salts affects the taste of the coffee on the one hand and the performance of the machine on the other (pressure reduction). Scaling is the most common fault that occurs in espresso machines, often with considerable repair costs. The process of removing scales is called "descaling". In professional machines, descaling is done using special filters that are placed in the machine's water supply. In household machines, descaling should be done by the operator using a suitable defatting product.
Keeping your espresso machine clean both inside and out will not only help you maintain the high quality of your espresso, but also extend the life of the machine without breakdowns and high maintenance costs.