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Espresso Machine Cleaning
Why, How, and When
By Dave Stephens
Exceptional espresso is the culmination of many factors. Obviously
the coffee itself is first and foremost, supported by the barista's
technique and the capabilities of the equipment. One factor that is
often overlooked in commercial establishments and homes alike is the
foul flavors that poorly maintained espresso machines can introduce to
the cup. As you will read, the sense of "clean" this article
advocates doesn't mean wiping down the driptray and running water over
the portafilters before closing, it means a regular cleaning regime that removes
impurities on an hourly, daily, and weekly basis. Don't be put off by
the detailed-oriented nature of the task—the reward is
genuinely better and more consistent espresso.
This article has several authors. Dave Stephens introduces
why cleaning must be a regular part of your barista duties
and how to perform them with step-by-step instructions
focused on the business-end of your espresso machine. Nick Griffith outlines when these cleaning
duties need to be performed. Finally, Chris Tacy explains the salient
differences between the cleaning regimes for home and commercial
establishments. The instructions and recommendations presented generally
apply to any espresso machine with a three-way valve type group; feel free to adapt these instructions to your own personal
use. In doing so, you remove one impediment standing between you and
Related: Grinders are not "self-cleaning" and can harbor rancid oils that taint your espresso. How to Clean a Mazzer Mini explains how to remove the burr assembly and
properly clean the grinding chamber.
Why? It's All About What's in the Cup (or not!)
The best coffee beans cannot make up for the impurities a dirty
machine adds to your drinks. Coffee beans contain essential oils. While
these oils are responsible for the rich crema that tops your espresso,
it can also be responsible for a rancid off flavor that develops over
time. Those oils emulsify and cling to and behind the water screen of
your espresso machine, doubly so on brass surfaces. These oils also
leave a film on the filter basket and portafilter. Over time this film
will start to plug the holes of the filter basket and create deposits
inside the portafilter spout. Luckily these impurities are relatively
easy to remove IF you follow a regular cleaning schedule.
Does this sounds a little excessive to you? Perhaps it will help to see what a portafilter might look like after a hard day at a busy café
if it's not cleaned properly (shown next to new portafilter):
Of course nobody should ever let their portafilter reach this degree of
filthiness. The results in the cup with be dramatic and unpleasant. Even
in a café this is not acceptable, though there one has the
(weak) excuse of being very busy.
Keeping your espresso machine clean will not only help maintain the
quality of your espresso but also extend the life of the machine. You
should purge and wipe off your steam wand after every use and run a
water shot through your machine after every brewing session. Do a clean water backflush every 10 to 15 shots and at the end of
every session as part of your cleaning routine. This section will
concentrate on the more detailed cleaning routine that should be
performed every week or 20 to 30 shots, whichever comes first.
IMPORTANT: Only machines with a three-way valves can be
cleaned using methods described in this article. If your espresso
machine does not have a three-way valve, do not attempt to backflush as
doing so can damage your espresso machine. Please consult your
operator's manual to verify the presence of the three-way valve (often
called a three-way solenoid).
Step-by-Step Cleaning Instructions
by Dave Stephens
Below we have a prime example of a dirty machine. There are milk
deposits on the steam wand and coffee residue and oils on the shower
screen. You should wipe off the shower screen with a moist cloth at the end of each session and the steam wand after each use (one dedicated to each task to avoid
cross-contamination). Once a week (or more often depending on your
usage), do a more detailed cleaning as described below.
You will only need a few items to
adequately perform your cleaning:
Espresso machine cleaner /
- Espresso machine cleaner (backflush detergent such as Cafiza,
PuroCaf, or JoeGlo),
- Blank, blind, or backflush portafilter basket (different names for the same item),
- A clean kitchen towel and a dishrag,
- Green scrubby (aka Scotch-Brite® pad) cut into 1 inch squares,
- Metal or glass bowl or container deep enough for the portafilter to
Optional components include:
- Group brush (my favorite is the smartly-designed Pällo Coffee Tool),
- Steam wand brush,
- Dairy cleanser (such as Urnex Rinza).
Start by simply wiping off the residue on your shower screen. Now
gather up your portafilter, backflush basket and flushing detergent.
Please read the instructions on your detergent and use their recommended
dosing. I am using JoeGlo. They recommend using ½ teaspoon of
detergent in your blind basket. Snap the blind filter basket into your
portafilter and add the recommended amount of detergent.
Time to flush and scrub
Follow the recommended flush sequence of the detergent you are using.
JoeGlo recommends running the pump five times in 15 second start/stop
intervals. Once the portafilter is locked into place, engage the pump.
You will notice a change in the pitch of your pump as the pressure
increases. Turning off the pump automatically opens a pathway from the
brew group to the drip tray; you will hear the distinctive "whoosh" as
the water escapes.
This release of pressure will force the dissolved detergent back
through the dispersion screen and the three-way valve. Flushing those
spoiled essential oils out of the system will not only improve your
espresso taste, but also clean the three-way valve of oils and grind
deposits so it seals properly. With some vibration pump machines, the pressure increase will
trigger the over-pressure valve to vent excess pressure back
into the water reservoir or drip tray. In this case, turn off the pump
once this occurs.
One trick to aid you in your cleaning after each session is the
"portafilter wiggle." Once you have backflushed with cleanser, loosen
the portafilter and hold it in place on the brew head. Engage the pump.
The blank filter basket will fill with water (and cleanser) until it
flows over the edge. Give the portafilter a wiggle to help clean the
oils and residue from the group head gasket. Be careful, hot water will splash! You
cannot see in the photo, but I have water splashing over the drip tray. If your boiler is at full temperature, this
water will be very hot, so take care not to burn yourself.
If you elected to purchase a group brush, this is where you will use
it. You need to clean any deposits from the portafilter gasket, the
group head threads that the portafilter locks into and the rolled edges
of the shower screen. Simply insert the brush into the group head and
scrub. I use a dishrag dipped into some dissolved flushing detergent to wipedown the gasket groove, using the groupbrush to guide the dishrag along.
Once completed, do not forget to brush and rinse the grouphead with clean water
(using the "portafilter wiggle" again) to remove any residual
After the flush sequence and portafilter wiggle, remove your
portafilter and drip tray. You many notice small coffee particles and a
dirty brown tint to the water. This is the gunk responsible for that
rancid flavor in your espresso.
Rinse out your drip tray and blank basket to remove any un-dissolved
detergent. If there is no detergent left and the water is still brownish
in color, you need to repeat the cleanser backflush with more detergent.
Careful, group head is hot!
Reinstall the drip tray and lock your clean portafilter back into the
machine and repeat the backflushing process with clean water. This time
you will be flushing out any remaining detergent from the brew group.
Refer to the instructions on your detergent for the recommended number
of cycles (generally the same number of cycles as for the detergent;
"rinse thoroughly" is the operative phrase).
Now that you have cleaned the internal workings via a backflush, you
can now clean the exterior surfaces. Simply wipe the shower screen with
Next clean the steam wand. Take the clean wet dishrag and wipe the
exterior down. If you have a steam wand brush, clean the inside of the
steaming wand (though if you need to use such a device, it indicates you
are not purging and cleaning your wand well enough after each use). Unscrew the tip
from the steam wand, dip the brush in an appropriate cleanser and run it
up the steam tube.
Note: Most backflush detergents are quite toxic and not suited
for this task. I recommend clean water. Urnex does make a product
specifically designed to clean steam wands called Rinza, and PuroCaf has
their own dairy cleanser as well. Both of these products work very well
and are highly recommended for soaking the wand and tip.
Remember to purge the steam wand after cleaning by opening the steam
valve and venting it into an appropriate container for about thirty
Soak the portafilter, basket and the steam tip
Now that the espresso machine is nice and clean, turn your attention
to the portafilter and basket.
Clean, shiny and ready to go
First, you'll need to rinse and wipe clean the basket. Second, you
should break down your portafilter (remove the spouts and disassemble
any cover the spouts may have). Once you've done this, take your green
scrubby square and thoroughly scour the inside surfaces of the
portafilter body and the spouts. Do not use the scrubby on your basket
as you will enlarge the holes.
Find a large container to hold them and pour enough water into the
container to submerge them. Add some of your cleaning detergent to the
water and stir to dissolve. Refer to the directions on your detergent to
get the correct dosing for the volume of water, JoeGlo recommends 1
tablespoon per quart of very hot water. Place your parts into the
detergent water and allow them to soak for at least ½ hour.
Note: It is inadvisable to allow the plastic, Bakelite or
rubber handle to be submerged in the water. Some handle materials can be
damaged by the cleanser and over time all will suffer rust and damage to
the internals of the handle.
After the soak, rinse all of the parts with clean water, repeat the
green scrubby scour, and then wipe dry with a dishrag. If the portafilter spouts are the open-slot type, visually confirm that there's no trapped oils the soaking didn't dissolve; use a small round brush to scrub it clean (don't laugh, but the brushes designed for cleaning baby bottle nipples are cheap and work well). Reassemble.
Spic and span
Wipe down the exterior of the espresso machine to remove any surface
dirt and reassemble. Now you are ready to pull shots and steam milk
until the next cleaning. Please note that it is always a good idea to
pull one garbage 'seasoning' shot at the beginning of the session that
follows a full cleaning. This assures that any residues are indeed flushed away and lubricates the surfaces of the three-way valve of lever-type E61 groups, eliminating "lever squeak" after a chemical cleaning.
Reminder: In addition to replacing the water in the reservoirs of pourover machines every other day, remember they need regular cleaning too!