Naked Portafilters

Naked Portafilters

In private correspondence with a few people, the issue of bottomless portafilters came up. They had bought one (specifically listed as for their machine, not marked as a generic product) from an on line retailer. These wouldn't fit E61 type machines(58mm portafilter) without having the existing 8.5mm gasket changed for an 8mm gasket (which was not supplied).

If you are buying a 58mm bottmeless (naked) portafilter, ask the vendor if it will fit on your E61 group machine without a gasket change. If they say "no", or "I don't know", move on and get one that fits, unless you fancy changing your gasket of course. If it says on the website that it fits your machine….then it should, without a gasket change (but still ask the question). E61 machines I know of, that now come with 8.5 mm gaskets in the UK are: All Isomacs with 58mm groups (except Venus), Izzo Alex & Vivi, Quickmill Andreja, Expobar….Pulser, leva, Brewtus II, Office control Machines. To be honest quite a few machines.

Also remember although the retailer may take it back….it's unlikely they will want to refund your postage!

There are indeed different portafilter and group manufacturers. The problem as I understand it doesn't lie in the group as these all appear pretty standard (made under licence). It seems to be the espresso machine manufacturers. In conversation with a major machine manufacturer last week, their reason for fitting 8.5mm gaskets was to prevent the group locking round too far (as an 8mm when it wears can lock round quite a long way. The 8.5mm was seen to just be more suitable and as it wears it still only locks just past 6 O' Clock at the most.

The problem definitely is the "ears" of the portafilter being…you guessed it 0.5mm thicker. The e61 groups I have measured (wherever they have been manufactured) all seem identical. Manufacturers are, however using different portafilters and depending on what they have chosen to use, dictates whether they use an 8.5 or 8.0mm group gasket.