How to Clean and Descale an Espresso Machine

Set out everything before you start so you are not hunting for parts mid-cycle. You need the portafilter, the single-wall filter basket, the rubber cleaning disk, a backflush cleaning tablet, descaling solution, and a fresh water filter for the tank.

Most espresso machines ship with a starter pack of cleaning tablets and descaler, but those run out. When they do, you can grab refills online for a few dollars. Any espresso-machine cleaning tablet and any coffee-machine descaler will work, not just the brand-name ones.

Drop the new water filter into a glass of warm water and let it sit for about five minutes. This wakes up the carbon and rinses out the loose dust so it works properly once it goes in the tank.

Start this at the very beginning of the clean. By the time you finish backflushing and descaling, the filter has soaked long enough to install at the end. It is an easy step to forget, so soak it first.

Load the portafilter in order: the single-wall filter basket goes in first, then the rubber cleaning disk sits on top of it, and a cleaning tablet drops into the dimple in the center of the disk. The disk has no holes, which is what forces water back through the group head instead of out the spout.

This blind-basket setup is how the machine cleans itself. The trapped pressure pushes the dissolved tablet up through the shower screen and washes out old coffee oils you cannot reach by hand.

Seat the portafilter in the group head and twist it firmly into the locked position. Then press the single cup, double cup, and power buttons all at the same time. Hold them until the buttons light up and the pressure gauge climbs.

That button combo is what puts the machine into its built-in clean mode on most home espresso machines. Once the lights are on, you can let go. The cycle runs on its own from here.

The clean cycle takes about five minutes. You will not see much come out, maybe a few drops from the portafilter, and the machine beeps twice when it finishes. Keep the water tank topped up the whole time so it does not run dry.

When it stops, pull the portafilter and look at the disk. If a chunk of tablet is still sitting there, it did not fully dissolve. Reload the portafilter, lock it back in, and run the exact same cycle a second time until the tablet is completely gone.

Now switch to descaling, which clears the mineral buildup that backflushing cannot touch. Pull the water filter out of the tank first, since descaler would ruin it. Pour in the descaling solution. Most bottles tell you to use half the bottle, so check the back label.

Top the tank off with cold filtered water up to the max line, then slide it back into place. The descaler and water mix on their own. Hard water is what causes the scale, so this step is what keeps your flow, temperature, and taste right.

Press the double cup and power buttons together until four lights illuminate, which tells you the machine is in descale mode. Put a big bowl under the group head to catch the runoff.

Press the single cup button. Water starts flowing through the group head and stops on its own after about twenty seconds. This is the first of three paths the descaler needs to clear, so do not move the bowl yet.

Turn the knob to the right to run descaler through the hot water spout for about eight seconds, then turn it left to push water out through the steam wand. Keep repeating the whole group-head, spout, and wand sequence until the tank is completely empty.

Once the tank runs dry, you are basically done. Drop the soaked filter into its holder, set it back in the tank, and refill with fresh filtered water. Your machine is clean, descaled, and ready to pull a better shot. If you also run a single-serve brewer, the same idea applies to descaling a Keurig.