How much do you think tamper size matters? I searched and found a few discussions on this, but nothing so directly related to the size of the tamper in relationship to the basket. Short of a custom made tamper, anything will leave some space between the edge of the tamper and the filter basket. However, after having spurt-all-over-the place extraction problems with a setup (the best I can afford) that has served me well for a few years, I tried using the ever-shunned 58mm plastic tamper that came with the machine instead of the 53mm rattleware that someone had given me. Obviously, I need to get a 58mm rattleware, but after weeks of trying many things to fix the problem, the tamper size seems to have been the issue. So, I'm just wondering if many of you who are more experienced than me would agree that the much-too-small tamper was in fact my problem, most likely causing side channeling.

-Thomas

HB wrote:I put the fit of the tamper piston to basket very far down on the list of important factors... within reason.

I generally agree with this...at least it is also what I have believed for quite some time.....

But AndyS has recently posted that he was able to actually measure a consistent difference in extraction yield using different sized tampers with the VST baskets.

I have no idea if this can be correlated to other baskets or if it's related to the VST technology in some way....but it's an interesting and surprising development that may warrant more investigation.

JonR10 wrote:But AndyS has recently posted that he was able to actually measure a consistent difference in extraction yield using different sized tampers with the VST baskets.

Not only that, but Andy claims "a huge improvement" going from a 58.0mm tamper to a 58.4mm tamper. If this wasn't coming from such an impeccable source, I'd discount it out of hand.

Fortunately for Spaz owners, VST baskets are not available in the 53mm size. So I feel no need to upgrade my tamper... yet.

RapidCoffee wrote:Not only that, but Andy claims "a huge improvement" going from a 58.0mm tamper to a 58.4mm tamper. If this wasn't coming from such an impeccable source, I'd discount it out of hand.

I doubt he tasted a "huge improvement" however, I ordered a new tamper just to be sure!! Anything that gives me a "huge improvement" for minimal dollars is a good investment!!

I still owe AndyS a "huge thanks" for the Robur sitting on my bar!

JonR10 wrote:...AndyS has recently posted that he was able to actually measure a consistent difference in extraction yield using different sized tampers with the VST baskets.

I remember when AndyS mentioned taste

RapidCoffee wrote:Andy claims "a huge improvement" going from a 58.0mm tamper to a 58.4mm tamper. If this wasn't coming from such an impeccable source, I'd discount it out of hand.

John, thanks for the shoutout, but in truth I'm every bit as "peccable" as anyone else around here.

I, too, discounted the tamper improvement out of hand at first. But after a short time, I couldn't ignore it.

PLEASE NOTE, however, I switched TWO things at once:

1. 58.0mm to 58.4mm dia
2. round bottom to flat bottom.

It is possible that the flat bottom has as much or more to do with the improvement than the exact diameter. Also, this is with a VST basket, which, because of its heavier construction, has less of a tendency to bow out at the bottom under 8 bars pressure. So with these baskets the flat tamper may be better than the round in maintaining a bed of relatively uniform thickness.

In addition, my "grooming" technique may have changed slightly. I used to try and optimize the appearance of the bottomless pour (even beading, early symmetrical cone formation, etc) because I assumed it would produce the best tasting extraction. But lately, I pay less attention to that. With the flatter-bottomed VST baskets the early beading is often not as even and it sometimes takes a long time for the cone to form. So be it -- the coffee is better.

cafeIKE wrote:I remember when AndyS mentioned taste

Actually, I said (twice) that the shots tasted better. To elaborate, with the round tamper they were rather tart, unsweet, and often lacking in character. Now, they are considerably sweeter, and more revealing of interesting flavors (plum, tangerine, roasted nuts, camphor, tar, etc, etc.) Not surprisingly (to me), the shots also measure "better": IOW, the extraction yield is now 19-20% whereas before it was 17-18%.

Editorial note: Although the "flavor is all that matters" cabal seems to hold this forum tightly in its grip, I find that the measurements are an extremely useful complement to all the tasting. Sometimes the measurements point me in the right direction when I'm confused or my tastebuds are simply burnt out.
Recently I was fortunate enough to visit Terroir Coffee. George Howell seemed to have measured the extraction parameters for every coffee he was testing. He is considered one of the top cuppers in the world, but he and his staff were routinely weighing and measuring everything. The best clean cup of Yrgacheffe I've had in quite a while was served to me by George that day.

So, I try to talk about both taste AND measurements, as do George, Vince Fedele, Scott Rao, James Hoffmann, and numerous top baristas worldwide.

Meanwhile, if anyone finds the VST baskets "hard to use," try a flat tamper 58.0-58.4mm in diameter if you're currently tamping with a round bottom.

Funny this topic came up. Recently I traveled with Cremina and once I arrived at the destination I realized I forgot tamper! Horror! Then I thought, wait a second, tamper is not that important, I can tamp using my fingers and just press the coffee down a bit uniformly and that is all there is to it.

And you know what? It worked great. I made as good espresso as I did when I used my nice Torr tamper.

Just something to think about...

Then only problem with custom tamper pistons is the inconsistency in baskets. If you have a tamper turned for a specific basket, chances are it will not fit the next basket even if that basket is from the same manufacturer. I also put the fit of the tamper way down on my priority list although I have never gone to great lengths to quantify any difference in a 58 vs 58.4mm basket. As long as the gap around the basket is reasonable I personally don't have an issue with it. In Europe the norm is to not tamp at all.

cannonfodder wrote:Then only problem with custom tamper pistons is the inconsistency in baskets.

This problem doesn't exist for VST and Strada baskets