How to Clean a Coffee Machine Properly… and the 3 reasons why you should

Cleaning a coffee machine – this isn’t the reason you become a barista (or bought a home espresso machine), but it’s still an important part of the job. You can’t just leave this for the closing staff, it’s important that you understand how and why you need to clean the coffee machine yourself!

3 Reasons Cleaning Your Coffee Machine Matters

Whether you’re in a busy café or making espresso at home like a boss, cleaning is not something you should skip, for 3 very good reasons.

1 – Cleaning Seriously Extends the Life of Your Machine

Coffee oils are acidic – leave them to soak in overnight and your machine will slowly start to deteriorate. Your group heads and seals will be the worst affected. The coffee oils will wear away the group seal and gather behind the shower screen, deteriorating the metal and blocking jets and filters our water passes through.

2 – Clean Your Machine For Clean Tasting Coffee

Lingering grinds and accumulated oils will first give you an overextracted taste, but over time as the oils build up, they’ll actually give your coffee a dirty rancid taste. The same goes for sloppy cleaning – if you leave any chemicals in the machine from improper back-flushing or over use of chemical (see below) your coffee will have a chemical taste.

3 – Hygiene – Wasn’t That Obvious?

You need to wipe down and maintain your machine so it’s sparkly clean. Rotting odours and hot, moist coffee environments will attract bugs and is a breeding ground for bacteria. Water used to make espresso is not quite at boiling temperature, so bacteria won’t be killed by simply flushing through with water. You must clean properly.  Unfortunately it is not uncommon to see  burnt and caked on milk on steam wands because people don’t wipe them following steaming milk. 

Cleaning Group Handles

Starting with the easiest and smallest part (albeit not actually a part of the machine) you need to clean your group handles.

Pop out the portafilter, give that a clean with warm water and a soft cloth, then move on to the group handle itself. These should never go in the dishwasher as that will seriously damage the handle.

You want to make sure that you clean in the lip of the group handle, the outside and the inside. You can use a little dishwasher detergent for stainless steel and brass group handles, but if you’ve got Teflon group handles, you’ll need to find a less abrasive cleaning product.

Pay careful attention to cleaning the elbow which extends to the spouts.  If you ever find large grinds of coffee in the bottom of your coffee cup and wonder how it made its way through the portafilter; the answer is it didn’t come from behind the portafilter.  It is a chunk of rancid coffee solid that has broken off the elbow of the group handle spouts.

Flush hot water through the group head into the group handle to clean inside the spouts.

Cleaning Group Heads

If you don’t clean the group heads after cleaning the group handles, or vice versa, you’ll just be transferring dirt from one to the other.

Turn on the water to run through the group head, grab your group head brush and use it to clean around  the group seal. Give the shower head a scrub too.

It’s really simple and only takes a few minutes, but this small action will stop coffee build up and deterioration of the group seal.

Blind Filters

A blind filter is a portafilter that doesn’t drain through. You just replace your portafilter with a blind filter, lock onto the group head and let the water pressure build up.

For commercial machines it’s absolutely imperative that you follow your machine manufacturer’s instructions on backflushing and ensure you do this at the end of each day’s trade.   I also highly recommend you backflush without chemical throughout the day during your quieter periods.

At the day’s end you need to back-flush with chemical cleaner – a white powder especially formulated for cleaning coffee machines. If you only use your home coffee machine once a day or less, you won’t need to use the chemical backflush daily, as long as you’re flushing the machine and group heads through with water regularly.  For home machines i suggest backflushing with chemical weekly.

Keep back-flushing until the chemical is all washed out, then backflush a few more times with water alone to ensure everything is clean and chemical free.

Behind the Shower Screen

Even when you back flush, coffee can be stubborn and stick behind the shower screen. You can easily unscrew or lever the shower screen off (or get your technician to do this if you’re working in a café – the last thing you want to do is damage company equipment) to clean behind it.

If you have any coffee grinds or oils behind the shower screen, this will block or divert the water running through, leading to uneven extraction in the basket.

Once clean, screw back in or secure back in place.

How Often Should You Clean The Coffee Machine?

Group handles – rinse throughout the day, wash clean daily.

Group seal – brush and rinse daily.

Group heads – flush with water regularly, chemical back flush daily.

Behind shower screen – weekly or less often for rarely used machines.

Steam wand – with each use.

Work surfaces – throughout the day.

Grinder – daily.

Tamper, tamp mats and dry cloth – daily.

Cleaning coffee machines is an important part of being a barista – that’s why I cover it in the Barista Level 1 Course. I can run you through the entire process of cleaning your equipment and machines, as well as give you a few tips on deep cleaning your group handles and keeping your entire workplace spotless.

Check out all of our courses or read other articles on this blog for more coffee tips! www.hgcoffee.com.au

The HG Coffee School Provides Barista Training In Adelaide, South Australia