How to Backflush an Espresso Machine (5 Easy Steps)

Last updated on February 7th, 2025 at 03:19 pm

Ever had your espresso suddenly taste… off?

I sure have. A few months ago, I noticed my shots from the Breville Barista Express were tasting bitter and uneven. At first, I blamed my grind size or tamping pressure, but no matter what I tweaked, my espresso just wasn’t right.

Then it hit me! I had completely forgotten to backflush my machine for weeks. When I finally did, the amount of old coffee gunk that came out was both horrifying and oddly satisfying.

After a deep clean, my espresso tasted fresh again, and I swore never to skip backflushing again.

If you want to avoid bitter shots and keep your espresso machine running smoothly, this guide will walk you through why backflushing matters, how often to do it, and the exact steps to follow. So let’s get started!

Key Takeaways

• Backflushing is essential for machine health – It removes coffee oils, residue, and buildup from the group head and internal valves, ensuring smooth operation and better-tasting espresso.
• Follow a regular cleaning schedule – Backflush daily with water, weekly with cleaning powder, and adjust based on usage to keep your machine in top shape.
• Avoid common mistakes – Using too much cleaning powder, not rinsing thoroughly, and skipping regular maintenance can negatively impact your espresso and machine performance.
• Invest in the right tools – A blind filter, quality espresso cleaner (Cafiza, Puly Caff), and a group head brush make the process easy and effective.

What is Backflushing and Why is it Important?

When I first got my Breville Barista Express, I knew regular cleaning was important. However, I didn’t realize how much buildup could accumulate inside the machine.

That’s why you must do backflushing. In other words, you deep clean your machine to remove old coffee oils, grounds, and residues from the group head and valves.

How Do You Do This?

For this, you use a blind filter (a filter basket with no holes) along with a specialized espresso machine cleaner, like Cafiza or Puly Caff, to force water and detergent back through the system.

This helps clear out internal pathways that are hidden from sight but can quickly get clogged with coffee gunk.

Why It’s Essential for Your Espresso Machine?

So let’s see more in-depth the importance of backflushing your machine:

• Prevents bitter-tasting espresso. Old coffee oils can turn rancid, affecting the flavor of your shots.
• Extends the lifespan of your machine. Regular maintenance keeps internal components working smoothly and prevents costly repairs.
• Ensures consistent water flow for perfect espresso extraction. A clean group head allows water to pass evenly through the coffee puck, improving shot consistency.

Signs Your Machine Needs Backflushing

Not sure if your espresso machine needs backflushing? Well, look for these signs:

• Espresso tastes off or bitter. If your shots suddenly start tasting stale or overly bitter, old coffee residue could be the culprit.
• Water flow seems restricted. A clogged group head or dirty valve can slow down water flow, leading to uneven extractions.
• Portafilter or group head looks excessively dirty. If you notice built-up residue, it’s a clear indicator that the inside of your machine is likely just as grimy.

Note: If your espresso isn’t tasting quite right or your machine seems sluggish, a thorough backflush can often bring it back to life. For this reason, regular maintenance makes a huge difference. It helps you consistently pull fresh and flavorful shots.

What You’ll Need for Backflushing?

Before you start, it’s best to have all your cleaning tools ready. I’ve found that using the right tools makes a huge difference in how well your espresso machine stays clean and performs over time.

Essential Tools & Cleaning Agents

Blind filter (backflush disk) – This replaces your regular filter basket and forces water backward through the system.

Espresso machine cleaning powder – Brands like Cafiza and Puly Caff are great for breaking down coffee oils and residue.

Group head brush – I use the Pallo Coffee Tool because its sturdy bristles make scrubbing easier, and it has a built-in detergent scoop.

Clean cloth or microfiber towel – Perfect for wiping down the group head and surrounding areas after cleaning.

Fresh water for rinsing – Essential for flushing out any leftover cleaning solution to keep your espresso tasting great.

Choosing the Right Cleaning Powder?

Not all espresso machine cleaners are the same. The reason is some are more aggressive than others, so you have to be careful. For instance:

• Cafiza is popularly used in both home and commercial because it’s strong enough to break down tough coffee buildup.
• Puly Caff is slightly gentler but still effective, making it a good option if you want a cleaner that’s easier to rinse out.

Note: Some machines, especially those with aluminum parts, may require a milder cleaner. I suggest always checking your espresso machine’s manual. You want to see if the manufacturer recommends a specific brand to avoid long-term damage.

Step-By-Step Guide to Backflush Your Espresso Machine

I use a Breville Barista Express for this example. If you own a different model, don’t worry because most machines with a three-way solenoid valve follow a similar cleaning process. So here are the steps you should take:

Step 1 – Prepare Your Machine

Before getting started, make sure your machine is off and has cooled slightly to avoid burns.

• Turn off the machine and let it cool if it’s been running.
• Remove the portafilter and inspect the group head for coffee residue or buildup.
• Insert the blind filter (backflush disk) into the portafilter. This is essential for forcing water back through the system.

Step 2 – Add Cleaning Powder

Now, let’s get the detergent to break down all that built-up coffee oil and gunk.

• Measure about ½ teaspoon of espresso machine cleaning powder (Cafiza, Puly Caff, or another recommended cleaner).
• Place the portafilter back into the group head just like you would when making an espresso shot. But instead of pulling a shot, you’re about to deep clean the internals.

Step 3 – Start the Backflushing Cycle

This step is where the magic happens. You’re going to flush out all the hidden buildup inside your machine.

• Run the pump for 10-15 seconds, then stop.
• Wait 10 seconds to let the cleaner dissolve and break down the oils.
• Repeat this process 4-5 times to fully flush the internal components. You might notice foamy or discolored water coming out of the drain. But don’t worry this is normal and means it’s working!

Step 4 – Rinse Thoroughly

You don’t want any cleaning solution left inside, so proper rinsing is key.

• Remove the portafilter and rinse it well under running water to remove detergent residue.
• Insert the blind filter back into the portafilter, but without cleaning powder this time.
• Run the backflushing process 3-4 more times using only clean water to fully flush out any remaining detergent.

Step 5 – Clean the Group Head & Portafilter

Now that the inside of your machine is clean, it’s time for some final touches.

• Use a group head brush (I personally use the Pallo Coffee Tool) to scrub away any lingering coffee residue from the group head.
• Wipe down the group head and surrounding areas with a damp microfiber cloth to keep everything spotless.

Note: I recommend adding this cleaning routine, and as I said, you’ll notice a huge difference. Next, I’ll explain how often you should do this process.

How Often Should You Backflush Your Espresso Machine?

So the big question is, “how often should you actually backflush?” Well, it depends on how frequently you use your machine and whether it’s for home or commercial use. Anyway, here’s a simple guide:

Frequency	Method	Who Should Follow This?
Daily (with water only)	Run a backflush cycle with just water to remove light residue.	Ideal for anyone who makes multiple espresso shots daily.
Weekly (with cleaning powder)	Use an espresso machine cleaner like Cafiza or Puly Caff to remove deeper buildup.	Recommended for home users who brew espresso regularly.
After 200 shots	A good rule of thumb for those who don’t track usage daily.	Works well for casual home baristas.
Every shift (for commercial machines)	Cafés and coffee shops should backflush with cleaner at the end of each shift.	Essential for keeping commercial machines in peak condition.

Note: If your espresso starts tasting bitter or your machine’s water flow seems restricted, it might be time to backflush, even if you haven’t hit the recommended schedule.

A quick water-only flush after each session can help prevent heavy buildup. Also, don’t forget to clean your steam wand while you’re at it. Because milk residue can build up as fast as coffee oils!

Common Mistakes to Avoid When Backflushing

I’ve made a few mistakes along the way. Some of them led to bitter-tasting espresso, and others made my machine work harder than it needed to. For this reason, here’s a few things to avoid:

1 – Using Too Much Cleaning Powder

When I first started backflushing, I figured more cleaner meant a deeper clean. Well, big mistake!

Using too much Cafiza or Puly Caff can leave behind chemical residue, which affects your espresso’s flavor. Plus, excessive cleaner can be tough to rinse out, especially on machines with smaller internal pathways.

Solution: Stick to the manufacturer’s recommended amount. Usually ½ teaspoon of powder. A little goes a long way!

2 – Not Rinsing Thoroughly

I’ll admit, there were times I rushed through the rinsing process, only to find my next shot of espresso tasting… well, off. Any leftover cleaning solution in the system can cause bitter, soapy-tasting espresso, which is the last thing you want after cleaning your machine.

Solution: After backflushing with detergent, always run the cycle 3-4 times with clean water to flush out any remaining cleaner. And don’t forget to rinse your portafilter and blind filter under running water, too!

3 – Skipping Regular Maintenance

The problem is coffee oils and residue can build up quickly inside your machine. This then clogs the group head, which affects the pressure.

Solution: Stick to a regular cleaning schedule—water-only backflushing daily if you use your machine frequently, and a full detergent backflush weekly. This simple habit keeps your espresso tasting fresh and your machine running smoothly.

Last Thoughts

Have any backflushing tips or lessons learned the hard way? Just drop a comment below! And if you’re unsure about your machine’s cleaning routine, feel free to ask I’m happy to help. and with that voilà!