Cleaning your coffee machine is crucial. You wouldn’t cook your dinner in a dirty pan, would you? The same applies to your coffee machine. Keep your coffee machine clean to ensure that you are achieving the very best coffee you can.
When making coffee, water flows from the boiler through to the group head. It then travels through the portafilter, the ground coffee, and finally into the cup.
When the shot stops, the release-valve (a three-way solenoid) releases excess pressure. In doing so it creates a vacuum, which sucks coffee, grinds and oils back into the group head and solenoid valve. As you can expect, over the course of the day these parts become very dirty which is why cleaning your coffee machine is crucial.
If the coffee oils are not removed on a regular basis, they will build up and turn rancid. A dirty coffee machine will make bad tasting coffee. Metallic, bitter or astringent flavours are often blamed on the barista, or even the coffee beans. We would argue that they are more often caused by dirty equipment.
My coffee machine has hardly been used – should I still clean it?
Many people assume that a machine with low usage does not need cleaning as often as a high usage machine does, but this is not true. The increased idling time of an inactive machine leads to oils becoming baked on to the group heads and portafilters. This is because there is no water running through them. Luckily, cleaning the machine is very easy.
Why is back-flushing important and when should I do this?
During service, do a rinse and some swilling with water every hour, or more often if possible. This will maintain the cleanliness of the group head. Keep a blind filter basket in a handle underneath your machine so that back-flushing is easy and fast. You can back-flush one group head at a time and still make coffee on the other ones. When you are busy you should pay extra special attention to frequent back-flushing.
At the end of the day, you must back-flush each group head with chemical cleaner, regardless of how busy the day was.
Learn more: Book a barista training session.