Good coffee does not only depend on its preparation. The cleanliness of the coffee machine also determines the taste. Above all, because of hygiene, they should even be cleaned every day.

Does your coffee taste rancid this morning? Kinda musty? This does not have to be due to the beans, but can be due to limescale and old coffee residues in the coffee machine. There are two more good reasons to clean the coffee machine a little more often: mold formation and electricity costs.

Every day you should do the following:

“Many calcified machines produce water that is too hot,” says Holger Preibisch, general manager of the German Coffee Association. “Due to the deposits, they can no longer maintain the water temperature.” Lime scale is deposited wherever water is processed. Therefore, experts as well as manufacturers of coffee machines advise emptying the water tank and wiping it dry even at the end of each day. The water exchange has another advantage: Fresh water does not negatively affect the coffee taste.

Even if the taste of the coffee seems to be the most important thing at first, there is a much better reason to put your hands on the machine every day: otherwise mold can form in it and germs can multiply. Moist coffee residues go moldy in the pomace for press residues, the coffee grounds container and in the drip tray. In addition, oils and fats from the coffee settle here. With capsule and pad machines, you should therefore empty the bowl after each use, recommends Theresa Seitz, consultant for small household appliances in the Association of the Electrical and Digital Industry (ZVEI).

According to Preibisch, this also applies to filters that should not be left in the holder after the brewing process. Even the cans of filter machines are best emptied daily when no more coffee is being drunk. Otherwise the coffee will dry up in it and the pot will be more difficult to clean.

The milk nozzle, the tank and their hoses in particular are tricky: “Germs appear wherever milk is used and not removed,” says Preibisch. The milk nozzle on the side of portafilter machines and fully automatic coffee machines, for example, can be unscrewed, placed in cleaning agent and then rinsed with clear water. Many of the devices remind you of this cleaning very regularly. From the expert’s point of view, the machine’s milk tank should be rinsed out every day. The same applies to the hoses, which are rinsed with hot water using the machine.

Descale monthly

The machine should also be descaled about once a month. That’s pretty easy. Usually, a lime cleaning agent is added to the filled water tank and a cleaning program or the usual preparation program is started.

Theresa Seitz advises against vinegar and citric acid, which are often used in the household against limescale. “Citric acid reduces the service life of the machines. The strong acid can attack seals and hoses.” Vinegar should also not get into the coffee machine. “It’s too sharp and can damage the plastics in the device.”

Regular cleaning cycle

Fully automatic machines and many other coffee machines remind you to start self-cleaning at regular intervals. “They provide enough pressure and temperature to clean the machines from the inside,” says Seitz. Nevertheless, cleaning agents are also needed to sufficiently dissolve fats and oils. “Depending on the manufacturer, these are tablets or powder that is first dissolved in water,” says Ansgar Pleye from the Specialty Coffee Association Germany, a network of coffee specialists. Fully automatic coffee machines have an opening for the tablet. With a portafilter machine, the powder or tablet is placed in the filter holder.

Attention: Even if the machine takes over many cleaning steps – some components have to be cleaned by hand. For example, this can apply to the brew group, the heart of the device. It can be removed from many devices and then simply rinsed off under clear water, according to Pleye. “If you do this regularly, you prevent lasting residues.”

With portafilter machines, the brewing group can be cleaned with a blind sieve. “Such a sieve has no holes, so that the hot water flowing through is flushed back under pressure,” explains the coffee expert. A tip for portafilter machines and filter devices: “If the grease on the sieve and filter holder is very stuck, you can briefly dip both in a hot water bath with coffee cleaner,” says Pleye. Deposits on the screen can be avoided by washing it out with water regularly, preferably even after each use, adds Preibisch.

Before each refill

Fats also settle in containers for beans or ground coffee. “You can remove the empty bean container from the machine to wash it out from the inside with a slightly damp cloth,” says Ansgar Pleye. Most containers are not suitable for cleaning in the dishwasher, the plastic in them becomes cloudy. Important: After wiping, the container must be allowed to dry completely before it is refilled.

(This article was first published on Tuesday, September 27, 2022.)