Clean your Mr. Coffee espresso maker by running water through the group head, backflushing the portafilter, and soaking removable parts in hot water with espresso machine cleaner

A Mr. Coffee espresso maker needs cleaning after every use to prevent old coffee oils and grounds from building up inside the machine. The group head (the part where the portafilter locks in) and the portafilter basket collect the most residue and are where problems start. If you skip regular cleaning, your shots will taste bitter or sour, and the machine may stop producing pressure.

The good news: Mr. Coffee espresso makers are straightforward machines with few parts, so cleaning takes about five minutes. You do not need special tools beyond a small brush and espresso machine cleaner powder, both of which cost under $15.

Key Takeaways

  • Flush water through the group head for 10 seconds after every shot to clear grounds before they dry inside the machine.
  • Backflush the portafilter by locking it in and running water through it for 2 to 3 seconds at a time, repeating five to six times until water runs clear.
  • Soak the portafilter basket and shower screen in hot water mixed with espresso machine cleaner powder once a week for 15 to 20 minutes.
  • Never use vinegar or descaling solutions meant for drip coffee makers, as they can damage the internal seals and valves of an espresso machine.

Flush the group head when ready after pulling a shot

The group head is the threaded opening where your portafilter locks in. After you pull a shot and remove the portafilter, run water through the group head for about 10 seconds without the portafilter attached. This washes out loose grounds and coffee oils before they dry and harden inside.

Point the group head into a sink or cup. Turn on the water lever or button the same way you would to pull a shot, but do not lock in the portafilter. You should see a stream of water come out. Let it run until the water looks clear and no more grounds are visible. This step takes 10 seconds and prevents buildup that would otherwise require deep cleaning later.

Backflush the portafilter five to six times

Backflushing forces water backward through the portafilter basket to dislodge grounds stuck in the small holes. Lock the empty portafilter (with no basket inside) into the group head. Turn on the water for 2 to 3 seconds, then turn it off. You will see water and grounds spray out of the basket. This is normal.

Repeat this cycle five to six times until the water coming out runs clear with no visible grounds. Each cycle takes about 5 seconds on and 2 seconds off. After the last cycle, lock the portafilter in and run water through it for 10 seconds without stopping, the same way you flushed the group head. This rinses away any remaining cleaner or loose material.

Do this backflushing routine after every shot. It takes less than a minute and is the single most important step to keep your machine working well.

Soak the basket and shower screen weekly

The shower screen is the flat metal disc with small holes that sits above the group head opening. The basket is the small metal cup that holds your ground coffee. Both collect oils and residue that do not come off with water alone.

Once a week, remove both parts and place them in a cup or small bowl filled with hot water (about 160 to 180 degrees Fahrenheit — hot enough that you cannot hold your hand in it comfortably). Add one teaspoon of espresso machine cleaner powder per cup of water. Let them soak for 15 to 20 minutes.

After soaking, use a small soft brush (a toothbrush works) to gently scrub the holes in the shower screen and the inside of the basket. Rinse both parts under running water until the water runs clear and you smell no cleaner. Dry them with a clean cloth before putting them back in the machine.

Clean the portafilter handle and spout

The outside of the portafilter handle and spout collect dried coffee and milk splatter. Wipe these down with a damp cloth after each use. If dried coffee has hardened on the spout, soak the portafilter in hot water for 5 minutes, then scrub with a soft brush.

Do not soak the entire portafilter handle in water if it has a wooden grip, as this can cause the wood to swell or crack. Wipe the wooden parts with a damp cloth only, and dry them right away.

Descale the machine every two to four weeks

Descaling removes mineral buildup from hard water that collects inside the boiler and pipes. Mr. Coffee espresso makers come with instructions on whether your model needs descaling, and how often depends on your water hardness. If your water is very hard, descale every two weeks. If it is soft, every four weeks is enough.

Use only espresso machine descaler, not vinegar or general-purpose descaling powder. Fill the water tank with a mixture of descaler and water according to the package directions. Run the mixture through the group head for 10 seconds, stop, wait 10 seconds, and repeat this cycle until the tank is empty. Then refill the tank with plain water and run it all through the machine the same way to rinse out the descaler completely. This takes about 15 minutes total.

If you skip descaling, the machine will eventually produce weak shots or no pressure at all, because mineral buildup blocks water flow inside the boiler.

What to avoid when cleaning

Never use vinegar, even though it works on drip coffee makers. Vinegar is too acidic and can damage the rubber seals and metal valves inside an espresso machine. The same goes for general descaling powders made for kettles or other appliances — they are not formulated for espresso machine materials.

Do not use abrasive scrubbers or steel wool on any metal parts, as this scratches the finish and can leave tiny metal particles in your machine. Stick to soft brushes and cloth. Do not submerge the portafilter handle in water if it has a wooden grip, and do not put any part of the machine in the dishwasher.

Never run the machine without water in the tank, and never pull a shot without water in the tank. This can damage the heating element and boiler.

Frequently Asked Questions

How often should I clean my Mr. Coffee espresso maker?

Backflush the portafilter and flush the group head after every single shot. Soak the basket and shower screen once a week. Descale the entire machine every two to four weeks, depending on your water hardness. Daily backflushing and weekly soaking prevent most problems.

What if water is not coming out of the group head?

The group head opening is likely clogged with dried grounds or mineral buildup. Backflush the empty portafilter five to six times as described above. If that does not work, descale the machine. If water still will not flow, the boiler may need professional service.

Can I use a regular coffee maker cleaner on my espresso machine?

No. Espresso machines have different internal materials and seals than drip machines. Use only espresso machine cleaner powder or descaler made for espresso machines. Regular coffee maker cleaners can damage the valves and seals.

Why does my espresso taste bitter even after cleaning?

Bitter taste usually means old oils are still inside the machine. Make sure you are backflushing after every shot and soaking the basket weekly. If you have been skipping these steps, descale the machine and then stick to the routine for a week — the taste should improve noticeably.

Is it safe to backflush my Mr. Coffee espresso maker?

Yes, backflushing is safe and recommended for Mr. Coffee espresso machines. Always use the empty portafilter (no basket inside) when backflushing, and never backflush with the shower screen in place. If your machine manual says not to backflush, follow the manual instead.