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When the Barista Express shows the CLEAN ME light, it wants a backflush: insert the gray cleaning disc into the single-cup filter basket, drop a Breville cleaning tablet on it, lock the portafilter in, then hold the 1 CUP, 2 CUP, and POWER buttons together for about 3 seconds. The machine runs an automatic 5-minute cleaning cycle, pushing detergent back through the group head and out the drip tray. Rinse the disc, basket, and portafilter, run one blank shot of plain water, and dump the first espresso after cleaning. This strips coffee oils; it does nothing about mineral scale, which is a separate cycle.
The full procedure
| Step | What to do |
|---|---|
| 1. Set up | Single-cup basket in the portafilter, gray rubber cleaning disc in the basket, cleaning tablet on the disc |
| 2. Lock in | Portafilter into the group head, empty drip tray in place, tank filled |
| 3. Start | Hold 1 CUP + 2 CUP + POWER ~3 seconds; the cycle runs about 5 minutes |
| 4. Check | Tablet should be fully dissolved; if not, run the cycle again |
| 5. Rinse | Wash disc, basket, portafilter; run a blank water shot through the empty portafilter |
Backflush vs descale, once and for all
The CLEAN ME cycle cleans the coffee path of oils and grounds sludge, the stuff that turns shots bitter and ashy. Descaling dissolves minerals inside the water path, the stuff that chokes flow and kills steam pressure, and it has its own mode and its own guide: how to descale the Barista Express. A machine on hard water needs both on different clocks, roughly tablets when the light asks and descaler every 2 to 3 months. Bitter shots after cleaning usually mean the grinder is the dirty part now: clean the burrs.
While the portafilter is out
Give the group head gasket a look: a brittle or cracked ring around the shower screen is why portafilters start needing a gorilla twist to seal, and it is a cheap part. Wipe the shower screen, and if flow through it looks patchy, unscrew and soak it in the same cleaning solution. Machines that still pull weak or sour after a full clean are usually a dose and grind problem, not a dirt problem; the dial-in cheat sheet is the systematic fix, and deeper symptoms live in Barista Express troubleshooting.
Related reading
FAQ
How do I start the cleaning cycle on the Barista Express? Cleaning disc and tablet in the single-cup basket, portafilter locked in, then hold 1 CUP, 2 CUP, and POWER together for about 3 seconds. The cycle runs about 5 minutes.
What does the CLEAN ME light mean? The machine has counted enough shots to want a tablet backflush of the group head. It is not a descale reminder; scale removal is a separate procedure.
Can I backflush without Breville tablets? Use espresso-machine cleaning tablets or powder (Cafiza-type). Do not use dish soap; it foams and lingers in the coffee path.
Procedure per Breville's BES870 instruction manual (breville.com).
Never miss a cycle: the free one-page Machine Maintenance Calendar (PDF) puts every daily, monthly, quarterly, and yearly task for espresso machines, drip, Keurig, and moka pots on a card you can tape inside a cabinet.
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