How to clean your espresso machine: a complete guide

Why Cleaning Matters

Coffee is oily. Every shot you pull leaves behind a thin layer of coffee oils, fines and residue on the shower screen, group gasket, portafilter basket and internal pathways. Over time, these oils oxidise and go rancid, producing a bitter, stale flavour that contaminates every shot you make.

A well-maintained machine produces noticeably better espresso. If your shots have developed an unexplained bitter or ashy taste that persists regardless of grind adjustments, a dirty machine is often the culprit.

Daily Cleaning (After Every Session)

These tasks take under two minutes and should become automatic.

Purge and Wipe the Group Head

After your last shot, run water through the group head for 2-3 seconds to flush out residual coffee. Remove the portafilter and wipe the shower screen and gasket with a damp cloth. This removes the wet coffee film before it dries and hardens.

Clean the Portafilter and Basket

Knock out the spent puck, rinse the basket under running water and wipe the inside of the portafilter. Do not leave a spent puck sitting in the portafilter. The trapped moisture and oils go stale quickly and will taint your next shot.

Wipe the Steam Wand

Immediately after steaming milk, wipe the wand with a damp cloth and purge steam for 1-2 seconds. Milk dries onto the wand surface within minutes and becomes extremely difficult to remove once baked on. If you forget and milk has dried, wrap the wand in a cloth soaked in hot water for a few minutes to soften the residue before wiping.

Never soak the steam wand tip in milk or water for extended periods. This can draw liquid back into the boiler through the steam holes.

Empty and Rinse the Drip Tray

The drip tray collects coffee, water and milk residue. Empty it daily to prevent mould growth and odours.

Weekly Cleaning

Backflushing (Machines with Three-Way Valves)

Backflushing forces water backward through the group head to flush out coffee oils and residue from the internal valve and passages. Most prosumer E61 and semi-automatic machines support backflushing. Pressurised basket machines and some entry-level models do not.

Check your machine's manual before backflushing. Machines without a three-way solenoid valve (like some Breville models and most lever machines) should not be backflushed.

How to Backflush

Water backflush (weekly):

1. 1.Insert a blind basket (a basket with no holes) or a rubber backflush disc into the portafilter.
2. 2.Lock the portafilter into the group head.
3. 3.Activate the pump for 10 seconds. The pressure will build and force water back through the three-way valve.
4. 4.Deactivate the pump. You will hear the valve release pressure and water draining into the drip tray.
5. 5.Repeat 5-6 times.
6. 6.Remove the portafilter and run water through the group head for 5 seconds to flush.

Detergent backflush (weekly or fortnightly):

1. 1.Add 1-2g of espresso machine cleaning powder (Cafiza, Puly Caff or similar) to the blind basket.
2. 2.Follow the same procedure as a water backflush: 10 seconds on, release, repeat 5-6 times.
3. 3.Remove the portafilter, rinse the basket thoroughly and run a water-only backflush cycle (5-6 repetitions) to rinse out all detergent.
4. 4.Pull a "sacrificial shot" (grind and brew into the sink) to flush any remaining cleaning residue from the pathway before making drinkable espresso.

Soak the Baskets and Portafilter

Fill a container with hot water and a small amount of espresso cleaning powder. Submerge the baskets and portafilter (without the handle if it is wooden) for 15-20 minutes. Rinse thoroughly. This dissolves baked-on coffee oils that daily rinsing misses.

Clean the Shower Screen

Remove the shower screen and scrub it with a brush under running water. Soak in cleaning solution if it has visible brown buildup. Coffee oils accumulate on the screen's underside and block holes, causing uneven water distribution across the puck.

Some machines have a shower screen that unscrews (E61 group heads). Others have a screw in the centre. Check your manual for removal instructions.

Monthly Cleaning

Descaling

Scale is mineral buildup (calcium carbonate) from hard water. It accumulates inside the boiler, pipes and valves, restricting water flow and reducing heating efficiency. Left unchecked, scale can permanently damage your machine.

How often: Depends on your water hardness. Very hard water may need descaling every 4-6 weeks. Soft water or filtered water may need it every 3-6 months. Test your water hardness with a TDS (Total Dissolved Solids) meter or test strips to determine your schedule.

How to descale:

1. 1.Use a descaling solution recommended by your machine's manufacturer (citric acid-based is common).
2. 2.Mix the solution with water according to the instructions and fill the reservoir.
3. 3.Run the solution through the group head and steam wand according to your machine's descaling procedure (check the manual).
4. 4.Flush with at least two full reservoirs of fresh water to remove all descaling solution.
5. 5.Pull a sacrificial shot before making drinkable espresso.

Important: Some machines with plumbed-in water lines or specific boiler materials (like aluminium) have different descaling requirements. Always check the manual.

Deep Clean the Steam Wand

Unscrew the steam tip and soak it in hot water with cleaning solution. Use a pin or thin wire to clear any blocked holes. Dried milk protein accumulates inside the tip and reduces steam pressure over time.

Inspect the Group Gasket

The rubber gasket that seals the portafilter to the group head wears out over time. If you notice water leaking around the portafilter during extraction, the gasket needs replacing. Most gaskets last 6-12 months with daily use.

Water Quality

The water you use has a bigger impact on taste and machine longevity than most baristas realise.

Too hard (high mineral content): Causes scale buildup. Damages the machine over time. Can make espresso taste chalky or flat.

Too soft (very low mineral content): Causes corrosion in copper and brass components. Can make espresso taste sharp or hollow.

Ideal range: 50-100 ppm TDS (total dissolved solids). A simple in-line water filter (like BWT or a carbon block filter) handles most municipal water. If your water is very hard, consider a dedicated water treatment system.

Some home baristas use custom water recipes (distilled water plus mineral concentrates) for precise control. This is advanced but can make a noticeable difference in flavour.

Cleaning Schedule at a Glance

When Cleaning Fixes "Bad" Espresso

If your shots have gradually developed a persistent bitterness, staleness or ashy quality that does not improve with grind or ratio adjustments, try a full cleaning cycle before changing anything else. Rancid oil buildup is one of the most common and most overlooked causes of bad-tasting espresso.

After a thorough clean, you may need to re-dial in your grind because the improved water flow changes extraction slightly.

Puck Yeah tracks your shot ratings over time so you can see whether a cleaning session improved your results. If your ratings jump after cleaning, you know your maintenance schedule needs to be more frequent.

Further Reading

• Best Espresso Grinders for Home includes maintenance advice for grinders.
• Espresso Grind Size Guide covers how dirty equipment affects grind consistency.
• Espresso Glossary defines backflushing, descaling and other maintenance terms.