What is a group gasket?
Espresso group portafilter gaskets are used to make the seal when you screw on your portafilter, when they age they go hard and brittle and end up leaking from the portafilter. If portafilter group gaskets are not changed frequently the rubber goes hard and can be very hard to remove. Typically when you try to remove the aged group gasket, it will come apart in pieces and small fragments will remain stuck in the group. Care must be taken to ensure these small fragments are removed otherwise the portafilter will be very hard to screw on.
A good practice is to change the group gasket every 6/9 months in a commercial environment and once a year for home use. You won't regret changing the gasket too frequently but you will if not changed in time. Old gaskets cause loss of pressure and loss of coffee cream during extraction. If coffee is dripping from the group during extraction - then the gasket has gone hard and needs to be replaced.
What are silicon group gaskets?
They are a vast improvement on the traditional gaskets that come preinstalled on coffee machines.
- They are easy to install and remove and don't break apart when removed.
- They do not smell, unlike some rubber gaskets.
- Silicon group gaskets are made from food-safe silicon.
- Cafelat and Repa DVM are the mail silicon gaskets for coffee machines.
How do you remove espresso group gaskets?
- Group gaskets are best removed using an awl or Gasket And O Ring Pick And Hook Set - simply insert the awl into the gasket at an angle and pull down the gasket - it should come down intact. You will notice when the group gasket is removed it will be hard and brittle and will break in two when pressed.
- When replacing the group gasket you should remove the shower screen and check that it is not blocked with burned carbonated coffee sugars - these particles contaminate the shot and add bitterness. If when the shower is viewed up against the naked light, and has more than 15% blocked - then you should replace the shower screen.
- Insert the new gasket after any debris has been brushed free with a group - use the portafilter to screw in the gasket fully. The gasket should sit at 6 o clock with a new machine and 7 if the machine is older.
- Supplementary Paper Shim Gasket will make the gasket thicker for older machines- so the portafilter sits at 6 o clock. Use a Rubber Shim Gasket if the group is well worn and it can be reused.
- The top tip for shower removal is to make sure you don't damage the screw - ensure the Shower Screen Screwdriver is at right angles and screw anti-clockwise "Lefty loosey and right tighty " applies. Replace the screw at the same time, to ensure the screw was not damaged.
BlueStarCoffee.eu carries most gaskets for most home and commercial coffee machines including Ascaso, Astoria, Bezzera, Breville, Brasilia, Conti, Cimbali, Delonghi, Gaggia, Lelit, Rancilio, Reneka, Fracino, CMA, Sage, Wega and more.
What is the difference between silicone and silicone rubber?
The difference between silicone and rubber is that most of the rubbers contain polymer chains of carbon, however, silicone rubbers contain silicon in polymer chains instead of carbon.
Is silicone plastic or rubber?
Silicone is a Plastic Polymer, although it may be referred to as synthetic rubber. However, it's slightly more complicated than that. Silicone, often known as polysiloxane, is a polymer composed of siloxane. Colorless oils or rubber-like compounds are the most common.