How to Backflush an Espresso Machine

Espresso can be an expensive and time-consuming hobby. First, there’s the money spent on the machine, coffee grinders, and coffee beans. Then there are the hours spent dialing in the perfect grind size, coffee dose, and shot timing. So why not spend an extra 5 minutes protecting your investment and ensuring your coffee always tastes great?

That’s backflushing for you. It’s quick, easy, and inexpensive, and there’s no reason not to do it. Keep reading to learn how to backflush your espresso machine.

Extra notes:

• Backflushing disc is also known as a blind filter or blank basket, this should be included with your espresso machine. It will either be a stainless steel or rubber disc designed to fit snugly in the portafilter.
• Some brands sell or require special cleaning tablets. But buying a jar of powder backflushing detergent is usually more affordable.
• Don’t be tempted to use anything not specifically designed for espresso machines. It might be less expensive, but it can permanently damage your machine.

How to Backflush Espresso Machine

Backflushing allows you to clean the inside of your espresso maker without having to open it up and take it apart. It flushes cleaning solution through the shower screen, group head, and three-way valve to remove built-up deposits of coffee grounds and oils. 

Note that you can only backflush espresso machines with a three-way valve. Those without typically have a different cleaning method dictated in the user manual.

If you don’t backflush regularly, the coffee deposits become stale and rancid, adding off-flavors when you’re drinking espresso (1). Additionally, coffee particles can cause clogs in the shower screen, which will impact water flow and cause uneven extraction (2).

Are you now convinced of the importance of backflushing when using an espresso machine? Good. Now let’s walk through how to do it.

1. Prepare your espresso machine

Ensure that the water reservoir is full and the drip tray is empty. Depending on the size of your drip tray, you may need to empty it periodically as you backflush, so keep an eye on it.

Some espresso machines have automatic cleaning cycles, in which case you follow the instructions in the manual to prepare the machine.

2. Prepare the portafilter

Pop the filter basket out of the portafilter and replace it with a metal or rubber disc. Add either one cleaning tablet or ½ teaspoon of backflushing detergent to the top of the disc, and lock the portafilter into place as though you were going to pull a shot.

3. Perform the backflush

Activate the brew cycle as though you were pulling a shot of espresso, using either the brew button or lever. Water will be pumped against the blind basket, and pressure will begin to build. If you have a brew pressure gauge, you can watch the increasing pressure there.

Listen carefully. After about 15 or 20 seconds, the machine will go quiet, indicating that the pressure built up to the full. Turn off the pump, and the three-way valve will blow the cleaner through the group head, releasing it into the tray where you’ll see soapy water emerge.

Repeat this process 5 to 10 times until the water released into the tray no longer looks frothy. The rancid coffee oils are now removed from the machine’s internals.

Many automatic and super-automatic espresso machines come pre-programmed with cleaning cycles – for example, Breville and Jura machines. Check your user’s manual, and if your machine has an automatic cleaning cycle, follow the manufacturer’s guidance.

4. Make sure the machine is free of cleaner

No one wants a soapy taste to their espresso, so this step is crucial. 

Remove the portafilter from the brew group head, and give it and the blind basket a good rinse in filtered water. Then set up to backflush again, but don’t use any detergent. Backflush twice more using only water.

Take the portafilter out again and run the pump for a few seconds to flush water through the system. Empty and clean the drip tray.

Final Thoughts

Backflushing an espresso machine is one of the easiest and quickest forms of maintenance. Once you’ve done it a time or two, you’ll probably be able to do it faster than you can read this article. And the results speak for themselves. Your machine will last longer, and the quality of your espresso will improve. Hard to argue with that!