How to backflush an espresso machine

Stale, bitter shots from a machine you clean every day? The residue is probably behind the shower screen. Backflushing clears it, but only on the right machines.

Last updated: September 2026

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The short version

Backflushing only works on machines with a three-way solenoid valve, such as the Gaggia Classic and Sage Barista Express, Pro and Dual Boiler. Put a blind (solid) basket in the portafilter, run water-only backflushes weekly and a detergent backflush with Cafiza or Puly Caff monthly. Sage machines do the same job with their cleaning disc, tablet and cleaning cycle.

Does your machine need backflushing?

When you finish a shot on a machine with a three-way solenoid valve, pressure is released backwards through the group head, and a little coffee and oil goes with it. Over time that residue builds up behind the shower screen and makes coffee taste stale and bitter. Backflushing forces water (and sometimes detergent) back through that path to clean it.

Many budget espresso machines, including the De’Longhi Dedica and Stilosa, don’t have a three-way valve. Backflushing them does nothing useful, and some manuals warn against it. If you’re not sure, look in the manual for “cleaning disc”, “blind filter” or “backflush”.

Water-only backflush (weekly)

Fit a blind basket (a basket with no holes) in the portafilter and lock it into the group head.

Run the pump for about 10 seconds, then stop. You'll hear the valve release and see dirty water come out of the drain.

Repeat five times, then remove the portafilter and run a short flush without it.

Detergent backflush (monthly)

Put about half a teaspoon (roughly 3g) of espresso machine cleaning powder, such as Urnex Cafiza or Puly Caff, in the blind basket, or follow the pack's dose.

Lock in and run 10 seconds on, 10 seconds off, five times.

Remove the portafilter, rinse the blind basket thoroughly, then repeat the water-only backflush five times to clear any detergent.

Pull one shot and throw it away before drinking the next one.

While you're at it, soak the baskets and the metal part of the portafilter in the same cleaner (not the plastic handle) to remove oil.

Sage Barista Express, Pro and Dual Boiler

Sage’s machines come with a silicone cleaning disc and use Sage cleaning tablets in a built-in cleaning cycle, which the machine prompts with its CLEAN ME light. It’s the same idea as a detergent backflush. See our Sage CLEAN ME light guide.

What you need

Urnex Cafiza espresso machine cleaner (566g)

The café standard

Cleaning powder
For backflushing & soaking

The espresso cleaning powder most cafés and machine makers point to. One tub lasts a home user a very long time.

£15.93

Puly Caff coffee machine cleaner (900g)

Big tub, Italian favourite

Cleaning powder
Backflush & soak

An Italian espresso cleaner in a large tub; the same job as Cafiza.

£11.45

Honiwu 58mm blind filter basket

For 58mm machines

58mm (Gaggia Classic)
Stainless steel

The solid basket you need to backflush a 58mm machine such as the Gaggia Classic. Check your portafilter size before buying.

£8.99

Sage cleaning tablets (16)

For Sage machines

Sage cleaning cycle
Use with the cleaning disc

Tablets for the Sage cleaning cycle on the Barista Express, Pro and Dual Boiler.

£11.99

Frequently asked questions

How often should I backflush my espresso machine?

With daily use, a water-only backflush weekly and a detergent backflush monthly is a sensible routine. Heavy users backflush with water daily.

Can I backflush a De'Longhi Dedica?

No. The Dedica has no three-way solenoid valve, so backflushing doesn't clean anything and isn't recommended.

What is a blind basket?

A portafilter basket with no holes. It blocks the water so pressure pushes it back through the group head and out of the valve.

Can I use Cafiza on a Sage machine?

Sage recommends its own cleaning tablets for the cleaning cycle. Check your manual before using other products.

How we write these: we don’t lab-test machines. Guides are based on manufacturer manuals and published specifications, and picks on specs, brand reputation and UK availability. How we choose.