I've been using a Synesso filter basket for some time in my old Duetto, and have just changed to a new Pullman basket in a similar size, possibly slightly bigger. I have made no other changes, the dose is the same, coffee is the same, tamp is the same etc., yet where the old basket used to release the puck intact with just a gentle tap, the new basket requires several hard knocks at which point the puck fractures and comes out in pieces. Each piece is of a similar look and feel to the pucks from the old basket, it just seems that the "stiction" between the coffee and the basket is higher than that which holds the puck together. The shot tastes the same and pulls in much the same time, it just won't knock out cleanly. The other users of the machine have said exactly the same thing (and requested the old basket be returned to service), so it's not just me! I can't see any other differences, the portafilter is removed as soon as it stops dripping and has a tiny amount of wetness on the surface which disappears almost immediately, perhaps slightly more with the new basket but not massively. The new basket is slightly deeper before it "bowls" inwards at the base, so there is slightly more headroom above the coffee, but not a huge amount.
From a coffee viewpoint it's not an issue - the end result is the same - but from a process viewpoint I now have to wipe out the basket to remove at the very least a thin coating of coffee and at worst "lumps" that are easier to wipe than to keep hammering on the knock-box. The Synesso basket used to knock out perfectly so the next shot could be pulled with zero mucking about.
So, any ideas why this is happening? Is it related to the slightly larger headroom? Size of holes in the filter? Surface coating or lack of it (i.e. simply age and use)? Or geometry of the basket? Or do I need to start playing with my carefully refined dose to suit the new basket?
Any thoughts?
From a coffee viewpoint it's not an issue - the end result is the same - but from a process viewpoint I now have to wipe out the basket to remove at the very least a thin coating of coffee and at worst "lumps" that are easier to wipe than to keep hammering on the knock-box. The Synesso basket used to knock out perfectly so the next shot could be pulled with zero mucking about.
So, any ideas why this is happening? Is it related to the slightly larger headroom? Size of holes in the filter? Surface coating or lack of it (i.e. simply age and use)? Or geometry of the basket? Or do I need to start playing with my carefully refined dose to suit the new basket?
Any thoughts?

Your theory sounds good but honestly I don’t know what the actual physics are I just know it made the difference I was looking for.. I wasn’t getting hung up on it but just couldn’t work out why the mucky pucks......Maybe that with the slightly increased dose size grind can be made ever so slightly more coarse which keeps the shot duration consistent but the larger amount of coffee in the basket is better able to absorb the remaining water.
" phile
Comment