How-to · Backflushing
How to backflush an espresso machine (Breville, Gaggia, prosumer)
Backflushing pushes water (with cleaner) backwards through the group head, removing coffee oils from the dispersion screen and 3-way solenoid. Machines without a 3-way solenoid (most Bambinos, super-automatics) cannot be backflushed traditionally — they need different maintenance.
This routine works for any semi-automatic with a 3-way solenoid: Gaggia Classic, Rancilio Silvia, Breville Dual Boiler, Lelit Mara X, Profitec Pro 300, etc.
What you'll need
-
Cafiza or Pulycaff backflush detergent (alkaline powder)
Cafiza is the industry standard. ~3 g per backflush. A 566 g jar lasts about a year of weekly backflushing.
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Blind basket (no holes) sized to your portafilter
Many machines ship with one; check the accessory tray. If missing, $15-20 from the manufacturer. Required — you cannot backflush without it.
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Microfiber cloth for the group head
Step-by-step
- Step 1
Verify your machine has a 3-way solenoid
If your machine relieves pressure with a "psst" when the brew stops (you can hear water/air discharge into the drip tray), it has a 3-way solenoid. If shots end silently and the puck is soup-wet when you knock it out, it does not — and backflushing will not work as intended. The Breville Bambino base model lacks a solenoid; the Bambino Plus has one.
- Step 2
Load the blind basket and dose Cafiza
Insert the blind basket into the portafilter. Add about 3 g of Cafiza powder — a level half-teaspoon. Do not overdose; more powder does not clean better, it just leaves more residue to rinse.
- Step 3
Run 5 short cleaning cycles
Lock the portafilter into the group head. Start the brew cycle for 10 seconds, then stop. Wait 5 seconds (let the solenoid release pressure). Repeat 5 times. You will see brown discharge in the drip tray — that is the coffee oils being purged.
- Step 4
Remove, rinse the blind basket
Unlock the portafilter and rinse the blind basket under running water until no Cafiza foam remains. Wipe the basket dry.
- Step 5
Run 5 rinse cycles with clean blind basket
With the empty blind basket (no Cafiza), lock back in and run another 5 short cycles. This rinses any residual cleaner from the solenoid and group head.
- Step 6
Wipe the group head and shower screen
Remove the portafilter. Wipe the group head gasket and the shower screen face with a damp microfiber cloth. If your shower screen unscrews easily (Gaggia, Silvia), pop it out monthly and soak it in a Cafiza solution for 30 minutes.
Common mistakes to avoid
- Trying to backflush a machine without a 3-way solenoid — the water has nowhere to go and you risk damaging the pump.
- Using too much Cafiza (>5 g per cycle) — leaves residue that takes 10+ rinse cycles to fully purge.
- Skipping the 5 rinse cycles after Cafiza — pulling coffee through a solenoid still coated in detergent makes the next shot taste like soap.
- Backflushing daily — once a week is plenty for home use. Daily creates wear on the solenoid for no maintenance benefit.
Frequently Asked Questions
How often should I backflush?
Weekly with detergent if you pull 2+ shots a day. Daily with plain water (no detergent) is also fine and recommended by some service techs to keep the solenoid free of grounds.
Can I use dish soap instead of Cafiza?
No. Dish soap leaves a surfactant residue that requires many more rinse cycles to clear, and the foam can over-pressurize the line. Use a purpose-made espresso machine detergent — they are designed to break down coffee oils and rinse cleanly.
What if my shower screen is dark brown / black with oil?
That means weekly backflushing was overdue. Unscrew the screen (one center bolt on most machines), soak in Cafiza solution overnight, scrub with a soft brush, reinstall. Going forward, weekly backflush prevents this buildup.
Does backflushing replace descaling?
No — they treat different problems. Backflushing removes coffee oils (alkaline cleaner). Descaling removes limescale (acidic descaler). Both are needed, on different schedules.
Last reviewed: . We update this guide when the manufacturer publishes new maintenance documentation or when community consensus on best practice shifts.