A Beginner's Guide To Coffee Machine Maintenance by James Hoffmann

Espresso Machines ☕

Maintenance for espresso machines focuses on three main areas: the portafilter and group head, backflushing the internal system, and descaling.

Portafilter and Basket: The basket should be cleaned every day, and the entire portafilter, including the inside, should be cleaned at least weekly using dish soap and a soft sponge. Never leave a dirty portafilter in a hot machine, as residual liquid will "cook down" and deposit material that tastes bad [02:56]. If it's very dirty, you can soak the metal part (not the handle) in hot water with espresso machine cleaner overnight.
Group Head/Shower Screen: The shower screen should be taken down and cleaned a minimum of weekly for a regularly used machine. Accumulation of old coffee here adds bitterness and harshness to your espresso. Use dish soap and rinse completely.
Steam Wand: Establish a habit of purging the wand after steaming milk and wiping it thoroughly immediately with a wet cloth. If there's dried milk, unscrew the tip and soak only the tip in hot water and detergent. Never soak the entire wand, as it could pull milky water back into the steam boiler.

Purpose: Back-flushing cleans the internal tube that runs from the three-way solenoid valve to the coffee, which accumulates coffee solubles after every shot.
Process: Use a blind basket (no holes) in your portafilter with a small amount of espresso machine cleaner.

Lock the portafilter in and run the pump for about 10 seconds.
Stop the pump, which releases the pressure and drags the detergent up into the machine to clean the valve system.
Repeat this process five times, doing shorter "on" times and longer "off" times.
Rinse the system thoroughly afterward until the water coming out looks and smells clean.

Prevention: To mitigate the need for cleaning, flush the group head immediately after pulling a shot (a 5-second flush is fine) to bring clean water through and remove residual coffee water.

Purpose: Descaling removes lime scale (calcium carbonate) that accumulates inside the machine, which can eventually lead to failure.
Frequency: Depends on your water hardness; generally every 6 to 12 months in low-scale forming areas.
De-scaler: You can use a commercial product or make your own using citric acid (e.g., 30g of citric acid per litre of water for a 3% solution).
1. Caution: Some manufacturers, particularly for machines with aluminium boilers (like some Gaggia models), caution against using citric acid. Always check your manual.
Process:
1. Empty the water tank and add the descale solution.
2. Turn the machine on and pump the water through the system to fill the boiler and tubes.
3. Switch the machine off and leave it for a while to allow the acid to break down the scale.
4. Turn it back on and flush the entire tank through the system.
5. Rinse the tank, add fresh water, and flush until the taste of sourness is gone (at least a full tank).

Grinder maintenance is key for consistent grind size and preventing bitter-tasting coffee.

Exit Chute: This is the most crucial part for regular cleaning. The exit point where coffee leaves the grinder needs to be kept clear at least weekly. If coffee accumulates, it leads to regrinding, which creates more fines and worsens the taste. Use the provided brush to clean it.
Hopper: If you store beans in the hopper, oils will deposit on the plastic/metal and turn rancid.
Regularly remove the hopper (once empty) and clean it with dish soap and water. Make sure it is completely dry before reattaching.
Burr Chamber: Getting inside to clean the burrs depends on how easy it is to open your specific grinder model.
If easy, brush out retained coffee and use a vacuum to hoover out the chamber. Some manufacturers suggest this is only necessary every 6 to 12 months.
Cleaning Agents: You can use specialised grinder cleaning pellets (like Grindz). Never use uncooked rice as it is harder than coffee, can damage the burrs, and will void your warranty.
Burr Lifespan: Burrs need replacing very infrequently, with a lifespan typically ranging from 250 to 500 kilos of coffee—potentially a decade for home users. Signs of dull burrs include a sudden increase in fines or the ground coffee coming out hotter than usual.

Filter Brewers (Batch Brewers/Drip Machines):
- Cleaning: Any part repeatedly touching coffee will accumulate residue. Use a soak in espresso machine detergent (hot water + detergent, soak for 30 minutes, then rinse) to clean carafes and brew baskets.
- Descaling: Descaling is necessary for performance, though failure is less likely than with espresso machines. Use a mild descaler solution (2% to 5% strength), brew halfway, pause for 30 minutes, finish brewing, and then flush with clean water.
Kettles: Descale using citric acid and hot water. You can just watch the satisfying chemical reaction happen. Rinse frequently.
Moka Pots: These need to be cleaned; the dark layer that builds up is dirt, not seasoning. The rubber gaskets inside the pot also need to be replaced when they become brittle or start leaking pressure.
Travel Cups: Soak in a small amount of espresso machine detergent and hot water to clean out old coffee residue.