WBC sensory judge and 2020 Italian Roasting Champion, Davide Cobelli, speaks to Jenna Gottlieb about the importance of descaling espresso machines and how prosumers can do it at home.

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Across the journey from seed to cup, obstacles at every turn threaten to ruin the distinct and subtle characteristics of a coffee. From heavy rainfall and bad storage practices to over-roasting and poor brew ratios, the list is endless.

However, few factors can be more damaging to the final taste of a coffee while also being easy to avoid than the buildup of limescale on an espresso machine.

Limescale is a chalky, sedimentary deposit primarily made up of calcium carbonate (CaCO₃) that’s more of an issue the harder the water used. As hot water is pumped throughout the machine, heat and pressure increase the amount of scaling left behind.

Espresso machines that are not descaled regularly can present numerous problems, and particularly badly maintained machines may break down completely, resulting in maintenance costs and voided warranties.

“The cleaning of espresso machines influences the quality of the cup delivered,” explains Davide Covelli, who works as a sensory judge at the World Barista Championship.

“Espresso machines, as with all tools and equipment, need to be restored to their original condition regularly. This is necessary to maintain the quality of the beverage, but also to extend the life of the machine itself.”

Without regular descaling, backlogs in the espresso machine may ultimately render it unusable and the espresso undrinkable. Thankfully, it’s relatively easy to descale modern espresso machines, especially those designed for home use.

With a descaling solution, vinegar, or citric acid – and a few simple processes – it’s quite simple to keep an espresso machine in good shape.

How often should you clean your espresso machine?

Davide reveals that ideally, an espresso machine should be cleaned after each use and at the end of each day, whether in a coffee shop or at home.

“Many automatic espresso machines have a kind of auto-cleaning mode that activates when you switch the machine off,” he explains. “However, it’s more a rinse than a cleaning, because they use just hot water.”

The primary difference between cleaning a traditional espresso machine and a superautomatic espresso machine, he says, is that they require different cleaning products.

Typically, there’s a wider selection of products for traditional machines, whereas superautomatics – especially home versions – can be easily descaled using widely-available chemical solutions.

“Always look at the user manual first to be sure and not damage the machine,” he points out.

In the case of traditional machines, it’s crucial to backflush regularly. For example, if a machine is used daily, it needs to be backflushed at least once a month. However, backflushing is not the same as descaling.

When backflushing, a filter is inserted into the portafilter, and hot water is allowed to run through it as it would for an espresso shot. The water is run for five seconds and allowed to sit for ten seconds, before it’s cleaned using a specific product and an abrasive brush.

This is repeated several times, and the process removes any coffee grounds or oils that have built up over time.

Other areas that should be cleaned regularly include portafilter baskets, shower heads, and the steam wand – which should be wiped down and purged between uses.

While not the same, cleaning and descaling an espresso machine serve similar functions. Both impact the inner workings of an espresso machine, help the machine operate at its best, and rid the machine of unwanted substances.

Ultimately, both cleaning and descaling are critical in getting the best performance out of your home equipment.

How to effectively descale your home espresso machine

Descaling equipment of any kind can be approached in a number of ways. However, Davide says the first place to start is by reading the user manual.

When it comes to superautomatic machines – such as the Carimali CA250, suitable for both home and office use – descaling simply requires the user to add a descaling solution to the water reservoir before pressing a button.

“There are some cleaning products on the market, but mostly one could simply use citric acid diluted with water,” Davide says. “I do not recommend using vinegar or lemon juice as an alternative.”

He says that this process should be performed once a month if tap water is being used, as tap water is the primary cause of scale buildup.

“If you use tap water, use a filter on the water reservoir,” he suggests. “There are descaling solutions on the market for these machines that work very well and are easy to use.”

However, he notes that traditional espresso machines – like the Elektra Verve – require a more complex approach.

“Traditional espresso machines are more difficult because it is a closed system and takes advanced skills to descale,” he elaborates. “It’s easier to maintain and clean the group head and backflush on these machines.”

Although many baristas and prosumers are quite knowledgeable about the inner workings of traditional espresso machines, Davide recommends hiring a professional to perform regular maintenance.

Once the machine has been opened up, special cleaning agents can be used to descale its boiler system.

“On the other hand, you don’t need to dismantle the machine often,” he adds. “A problem or a machine stop caused by an internal issue is very rare and very complicated to solve.”

“This is not a beginner process,” he reiterates. “You need advanced skills.”

Ultimately, descaling is vital to maintaining a home espresso machine, whether it’s a superautomatic machine or a traditional one. If done regularly, correctly, and with the right cleaning agents, the machine should continue to produce delicious coffee for years to come.