An espresso machine gets worse gradually and the owner adapts without noticing. Here is the routine that stops it.
After every drink
- Purge the steam wand for a second and wipe it while the milk is still wet. Milk gets drawn back into the wand as it cools, and it sours in there.
- Knock out the puck and rinse the basket. A puck left in a warm portafilter for a day is unpleasant to remove and leaves a residue.
After every session
- Flush the group for a few seconds with the portafilter out. This clears grounds off the shower screen.
- Wipe the shower screen with a cloth. Thirty seconds, and it stops the slow build-up that eventually needs solvent.
Weekly
- Backflush with a cleaning tablet, if your machine has a three-way solenoid. Blind basket in, tablet, run the pump in short bursts, rinse thoroughly. This is what removes the oils above the screen that flushing cannot reach.
- Soak the basket and portafilter in cleaner and hot water for twenty minutes. Not the plastic handle. You will be unpleasantly surprised the first time.
- Empty and wash the drip tray properly. It is where scales go to die and where smells start.
Monthly
- Take off the shower screen and the dispersion block — usually one screw — and soak both. This is where the worst of it hides.
- Check the group gasket. When it hardens, the portafilter starts to sit further round and eventually leaks. It is a cheap part and a five-minute job.
What happens if you skip it
Old coffee oils are bitter and they are in the path of every shot you pull. The change is gradual enough that you adjust your grind to compensate, then your dose, and conclude the machine is not what it was. It usually is — it is just dirty.
Questions people actually ask
What is backflushing and does my machine support it?
Forcing water backwards through the group using a blind (unperforated) basket, so it flushes out the oils that collect above the shower screen. It only works on machines with a three-way solenoid — a Gaggia Classic yes, most thermoblock machines no. Check before you try.
How often should I backflush?
With water after every session takes ten seconds and is worth doing. With a cleaning tablet, weekly for heavy use and monthly otherwise. If the water coming out is brown, you have left it too long.
Why does my steam wand smell?
Milk left inside it. Purging the wand for a second after every use clears the milk that gets drawn back up as the wand cools. Wipe the outside immediately too — baked-on milk is far harder to remove than fresh.
Last reviewed 8 August 2026
