Have you been neglecting your Group Head Gaskets? 

Because they’re in an out-of-the-way spot, group head gaskets tend to be one of the unsung heroes of the coffee world, putting in countless hours of service and demanding little maintenance in return.

But every once in a while, those gaskets can turn on you, introducing off flavours to your brew or getting cranky and starting to cause leaks on the top of the portafilter over time.  In either case, your gaskets are going to need a little attention to get things back to optimal brewing order.

Cleaning the gaskets with a backflush is an often-neglected step.  You might be shocked the first time you swap out an old gasket to realize how dirty things can get in there.  Backflushing is an effective step to get out deeply seated grime, but it involves harsher chemicals than you’d normally use on your machine, so be sure to rinse everything out with a full cycle after you do it.

Here is the step by step o how to backflush you espresso machine: 

But what if cleaning doesn’t solve the problem? Or perhaps you have a leak, or your old seal has fossilized, sealing itself in place and threatening to crumble if you pry it out for cleaning? Sometimes, you need a brand-new gasket.  

If you’re looking for high-quality alternatives for easy cleaning and removal, you’ll find two great choices: silicone seals and nitrile rubber.

One of the reasons group head gaskets are so often neglected is because they can be a real pain to pry out when they get old and stuck.  This is because inferior rubber gaskets often harden up with time and temperature stress.  Unlike traditional rubber gaskets, silicone gaskets won’t harden up, meaning you’ll have a much easier time swapping them out either for cleaning or for replacement.  

Silicone seals offer all the advantages of silicone, a material that has rapidly been adopted for a wide range of cooking and baking applications because of its superior temperature resistance as well as its availability in a wide range of bright, easy-to-spot colours.  Another huge advantage of silicone is that it doesn’t pick up flavours or smells, so every shot will be fresher-tasting, with fewer residues.

Silicone stays soft and leak-free much longer than traditional rubber, and the softer material also means there’s going to be less strain on your wrists because the gasket is held snug against the edge of the basket with much less effort.

However, never use a sharp tool like a knife or a screwdriver to remove silicone gaskets, because they could damage the material.  Fortunately, because they’re softer, you’ll probably have a much easier time removing them, no matter how old the gasket is.  

Your other great option is nitrile, or NBR rubber.  This is a synthetic rubber that’s ideal due to its higher resistance to oil and acids than standard rubber, and a very broad range of temperatures at which it stays durable and flexible.  In fact, these are just a few of the reasons it’s been so popular in the automotive and aeronautics industries. These are a terrific low-cost option that will serve you faithfully and remain trouble-free for excellent coffee over and over again.

All group head gaskets / seals should be replaced periodically, based on volume.  In high-volume applications, you may find that they need replacing every 3-4 months; otherwise, every 6 months is best for optimal brewing.

One final hint: if you’ve swapped out the gasket but are still experiencing leaks, there may be a problem with the edge of your portafilter basket.  Over time, with repeated banging to knock out the puck, there may be small dents and dings in the edge of the basket.  The gasket can help prevent leaks, but a dented basket won’t meet up with the edge of the gasket and under pressure, some water is bound to start getting through. Check the basket options we carry HERE and don't miss a great cup of coffee today!

No matter what type of gasket you choose, it’s a good idea to keep a couple of backups on hand.  Blowouts aren’t common, especially with high-quality materials and regular cleaning, but Murphy’s Law says they’ll always happen at the worst possible time – and fortunately, it doesn’t cost a lot to be prepared!