Pullman have developed a precision and accurate portafilter basket to enhance even extraction. Pullman have established an excellent name for themselves with their quality tampers. The baskets are another product made to their high standards.
The baskets come in three sizes: 17-19g, 19-22g, 22-25g
What Pullman says about the baskets:
‘The single largest problem we encounter with filter baskets is the large deviation of internal diameters between and within manufacturers.
We invent and design products that will help coffee consumers have a better coffee experience and these products deserve the best filtration system to work within. This has prompted us to take control and produce our own range of ridgeless filter baskets designed for a 58mm group head.
A Pullman tamper, perfectly matched to a Pullman filtration basket means more control over the variables affecting espresso extraction and a superior outcome for you, the coffee maker and consumer.
Possibly the biggest piece of mind here is knowing that multiple baskets bought (eg for a 3 group machine) will all be within spec and matched in internal diameter size by us.’
Pullman Filtration basket specs:
– guaranteed internal diameter of 58.7 +/- 0.15mm
– hole diameter of 0.3 +/-0.02mm providing a consistent and uniform performance for the life of the basket
– electro polished, no burrs, no scratches, no misshaped holes
– AISI 304 material which is compliant with Europe Food Contact Directive, FDA and ROHS
Here’s four comments in favour of a ridgeless basket over ridged
1) The diameter of the basket is not always the same above and below the ridge. If the basket is smaller below the ridge, the tamper will bottom out on the ridge making it impossible to apply much tamp pressure to the coffee below the ridge, resulting in an undertamped puck. If the basket is larger below the ridge (as happens with baskets with an inwardly-formed ridge) then a ring of completely untamped coffee will exist around the edge of the basket which the water will immediately find and escape through. The bottom line is that any variation in basket diameter through the majority of the height of the basket will lead to uneven tamping which can greatly affect how evenly the espresso is extracted. With a ridge this situation is more likely to present itself.
2) With no ridge there is a greater chance of the basket being more uniformly circular, presumably because the ridge-pressing process deforms the basket slightly. Depending on the amount of distortion (and we’ve seen pretty ovoid baskets in our time!), a fitted tamper can be more difficult to achieve which can lead to less than ideal extractions.
3) A ridge potentially creates a weak spot in the puck for peripheral channelling to start. If you’re tamping below the ridge this isn’t going to be an issue but that’s not always the case.
4) All other things being equal, pucks knock out a lot cleaner from a ridgeless basket vs a ridged. A ridged basket often leaves a smattering of puck stuck in the ridge. With a ridgeless basket the basket is normally pretty clean, needing only a wipe before the next shot as opposed to a wash and dry. Less of an issue if you dose below the ridge.
(Above comments courtesy of Pullman, from www.thingscoffee.com.au,)