How much do you know about coffee machine maintenance?

After long-term brewing of coffee, if the coffee machine is not cleaned in a timely manner and is left for an extended period, the brew head will be completely covered in coffee stains. Over time, the coffee residue will harden into clumps, becoming dirty and unsightly.

To address this issue, let's talk about the importance of maintaining a coffee machine. Before this, let's return to the essence of the problem that the working principle of a coffee machine. The working principle of a coffee machine is quite simple: all espresso machines operate by applying pressure to the water used for brewing coffee. When it comes to extraction issues, the quality of water is usually discussed, and the same is true for coffee machines. The impact of water on a coffee machine is critical. We can confidently say that water is the "blood" that flows through the coffee machine.  

Part 1. The Importance of Water

We will elaborate on the importance of the water flowing through the coffee machine by discussing the following points:

1. Water pressure
2. Water quality
3. Water temperature

Water Pressure: 

Water pressure generally comes from the external tap water supply. The stability of this pressure affects the accuracy of the water output during the extraction process. The volume of extraction water is one of the key elements in coffee extraction, and a more stable water pressure will certainly beneficial for extraction. Therefore, we do not recommend using bottled water for commercial coffee machines for an extended period. Additionally, a water source without pressure has the drawback of air often getting mixed into the water pipes, causing the water pump to run dry, which can also negatively impact the lifespan of the pump

Water Quality:

The hardness and softness of water, microbial content, and various regional factors are the primary variables that cause different flavor profiles in extracted coffee. Since 98% of a cup of coffee is water, we recommend that customers install a water purifier or softener after purchasing a coffee machine, as water quality varies across different regions. Ensuring good water quality is the greatest respect for coffee.

So, does having a water purifier or softener guarantee that the water quality in the coffee machine will remain good for a long time? Not necessarily.

The main water quality issue with coffee machines is the problem of limescale. The electric kettle we commonly use at home develops a layer of white, powdery substance at the bottom after some time, which is limescale. The same happens with coffee machines. The hot water used for extraction and the steam used for frothing milk are both heated in the boiler. Frequent use leads to frequent heating, which accelerates the buildup of limescale.

What are the damages caused by limescale to coffee machines?

1. The metal heating element of the coffee machine can become oxidized due to long-term use and limescale buildup, which not only reduces heating efficiency but also damages the insulation layer of the inner tank. This can prevent the heat from being transferred to the water in a timely manner, causing the temperature to become too high and potentially leading to the bursting of the heating element, resulting in the water becoming electrified and causing electric shock incidents.
2. Limescale can clog water pipes, affecting the smooth water output of the machine and the extraction process.
3. It can corrode machine components, accelerating the aging of the machine's sealing rings and shortening its lifespan.
4. High levels of calcium and magnesium ions can accumulate, causing the water to become hard, which greatly impacts coffee quality.

Limescale is the primary factor that reduces the lifespan of coffee machines and is also the main reason for bad-tasting coffee.

Water Temperature:

The importance of this point goes without saying. Most people brewing hot coffee use a thermometer. The same goes for coffee machines, which have been developed with water temperature settings as a key focus. Generally, professional coffee machines come with temperature control settings. The stability of water temperature is indeed a significant factor in the extraction process. However, you can rest assured that modern coffee machines generally come equipped with independent multi-boiler setups and PID temperature control technology.

Part 2. The Importance of Daily Maintenance

Let's talk about the management of daily maintenance points for coffee machines.

Filter basket of portafilter:
To make a cup of delicious coffee, the first part that needs to be kept clean at all times is the portafilter basket. It consists of two components, the portafilter holder and the filter basket, which has very fine screen holes. As we all know, espresso machines extract coffee under high temperature and pressure, resulting in concentrated coffee that contains thick coffee oils. Therefore, the filter basket can easily become contaminated with coffee oil residue, which cools and adheres to the surface of the container and can decompose when heated. If the oil residue on the filter basket is not cleaned in a timely manner and used for extraction, it results in a cup of coffee containing unpleasant flavors from the previous coffee oils (which can spoil). The quality of espresso is influenced by these external factors, making it impossible for that cup of coffee to taste good.
How to clean it? The filter basket holds the coffee grounds, so it needs to be unclogged. The portafilter holder is the drainage channel for the coffee liquid and is a hotspot for coffee oil residue. When cleaning, separate the filter basket from the portafilter holder to thoroughly remove stubborn stains.

The steam wand used for frothing milk is also a part that must be kept clean at all times. Because steam is hot, and milk foam is created by steaming cold milk. During the transition from cold to hot, the steam wand can become coated with milk foam. If it is not cleaned in time, the milk foam will form clumps on the steam wand. Over time, the accumulated milk will definitely start to smell bad. It's essential not to let milk residue clump up on the steam wand. When making coffee, we must have a clean, damp cloth on hand to wipe the steam wand immediately after frothing milk.

What are the consequences of repeatedly using a steam wand with milk residue to froth milk without cleaning it? First, the quality of the milk foam is compromised from the start, severely affecting the taste of specialty coffees. Spoiled milk foam can harm consumers' health. Second, the clumped milk residue can clog the steam nozzle, which greatly impacts the quality of the milk foam.

As mentioned above, the brew head is key to making delicious coffee because it is the outlet for the water required for extraction. Like the portafilter, the brew head consists of two parts, the filter screen and the water outlet bracket. During the extraction process, stubborn coffee oil residues accumulate on the filter screen due to the back pressure when extraction stops. If not cleaned for a long time, this can lead to clogging of the filter screen, which results in the hot water outlet being contaminated first.

An independent brew head continuously provides heat, which can roast any residual coffee oil. The dried oil can clog the fine holes of the filter screen, causing uneven water flow and greatly impacting ideal extraction. Additionally, because there is a sealing ring on the brew head, another downside of not cleaning the brew head is that it accelerates the aging of the sealing ring. The aging of the sealing ring can lead to air and water leaks, which affects the machine's lifespan and coffee quality.

So, it is necessary to regularly use a cleaning brush to remove any remaining coffee grounds to clean the brew head filter screen.

The drip tray is used to direct wastewater, so it tends to accumulate coffee grounds and coffee liquid. If it is not cleaned for a long time, it will form a sticky residue, making future cleaning more difficult. Maintaining cleanliness and hygiene is crucial in coffee-making. Therefore, when the machine is not in use, we should clean the drip tray with clean water to ensure that no other substances are left behind.

The top cover of the coffee machine is designed as a cup warming area to facilitate and save time on warming cups. Most people think that cleaning the top isn’t very important, especially since it looks clean, but that’s not the case. The original design intention is to dissipate heat, allowing the hot air from the boiler inside the coffee machine to escape. Therefore, it features a perforated filter plate. Dust and small coffee grounds can easily float in, and the accumulation of dust is certainly detrimental to the lifespan of the coffee machine. It is also very important to wipe the cup warming area with a damp cloth every day.