Come on, Jon. You know that anything with a tolerance and that changes with temperature could have the same issue. It maybe less likely on a premium basket, but the certainty still exists that a custom fit for a + tolerance basket will stick in a -. That's why gauge pins are made in + and - versions.

I'd like to see a blind test over several weeks for several coffees wherein a 3rd party randomly swapped identical, save diameter, 58 and 58.4mm tampers and the uber-barista has to say which was which, either by taste or beading or extraction ratio.

cafeIKE wrote:Come on, Jon.

Oh come ON Ian,
You have shown a general ignorance regarding this product, and you rigidly refuse to engage in any reasonable conversation or discourse about it (as far as I can tell). Therefore I have concluded that interacting with you on the subject of VST baskets is nonproductive.

There are a couple of problems with using a tamper that fits snugly in the basket. First, if you pull the tamper out quickly, a vacuum can be created and the puck may be dislodged. In my experience, this can be mitigated by pulling the tamper out slowly. Second, there may not be enough clearance to do a nutating or NEWS tamp to seal the edges. This can be mitigated to some extent by running your thumbs around the outside edge of the tamper base while it's sitting on the puck.

Nonetheless, after reading Andy's post I decided to order a Reg Barber 58.4mm flat tamper to use with my VST baskets. The primary motivation was to try a flat tamper (which I've never used), and secondarily to follow Andy's recommendation exactly. I measured the baskets with a digital caliper and it looks like 58.4 mm will work, but just barely. If I have problems, I can always get Reg Barber to take it down a mm for $20.

I just picked up 4 EP-HQ baskets for a friend with a new cafe; double and triple ridged and ridgeless. My 58.4mm tamper fit all four baskets and still had a little play. Just saying.........

Responding to Andy and Dick's comments in particular, but not with reference to the VST:

I have to admit that I also prefer the results and consistency I get with a flat tamper. This surprised me as a tamper sceptic/agnostic but have been forced to acknowledge the difference and consigned the C-flats I bought on hearsay to duty as paperweights.

I have RB 49 and 49.2 tampers for my lever machines and have yet to notice any massive difference in the cup between, but haven't done any systematic comparisons either. If nutating, I tend to do this almost as a separate levelling movement before tamping down, so although it's more awkward with the larger tamper it's not impossible unless really downdosing - however I find simply tamping works as well or better with the tight fitting one. Whether that's because the nutating can't work properly or the tight fit and fat RB base work miracles of their own is a mute point. I feel I may have to play around with this a bit, drawing in some guinea pigs just to satisfy my curiosity....