Does anyone have any idea why a double tamper would be useful? I came across one made by Elektra (Edit: should read Isomac although Elektra does one as well) that is 53 mm diameter on one side and 58 mm on the other. The only thing I could think of is if your basket has tapering sides, then you would use one side for a single and the other for a double.

in some cases with a single portafilter basket the 53mm is used to tamp ... its an italian style thing if i remember correctly. Ive never done this but this is the answer i got when asking why also.

maybe someone else can clarify

Mark

It may be a "generic" tamper to cover two popular basket sizes, 53mm and 58mm. I think that La Marzocco calls out specific sizes for their single and double baskets (IIRC, 57mm and 40mm; corrections welcome).

HB wrote:It may be a "generic" tamper to cover two popular basket sizes, 53mm and 58mm. I think that La Marzocco calls out specific sizes for their single and double baskets (IIRC, 57mm and 40mm; corrections welcome).

Do most manufacturers have different diameter baskets for their singles and doubles? If so, is there a technical reason why? At first glance, I can't see any reason against using only one basket, and dosing as per requirements.

Most single baskets have sloped sides, so you can press them into service using the same tamper as the double basket. The La Marzocco baskets are more cylindrical, thus the same 57mm tamper would not work. To see what I mean, Google images is quite helpful ("la marzocco single basket").

Dan I'm assuming that for a single the basket is only filled as far as the taper. Is this for quick and easy measuring by volume?

Most Italian manufacturers assume the barista will use the doser; one pull, 7 grams, two pulls 14 grams. I don't believe the strike off method you mention is commonly used in Italy. Or, for that matter, based on my brief visits, a barista in Italy is more likely to use the tamper head mounted on the grinder and tamp by pulling up on the portafilter.

OK. What I'm not getting is why taper at all?

Dan spoke to this above. If what you actually meant is "why reduce cross-section?" (with or without a taper in between) I expect it's to achieve similar flow per unit area of cross-section as in the double basket, avoiding a change in shot time or grinder setting after switching baskets. In practice, well. . . .

Incidentally, after a career of tossing the ubiquitous convex black plastic freebee tampers, I found that my last one was ideally sized for tamping the L.M. single, using first the small end and then the large. If I used the single basket more often, I might get a proper tamper.

genovese wrote:Dan spoke to this above. If what you actually meant is "why reduce cross-section?" (with or without a taper in between) I expect it's to achieve similar flow per unit area of cross-section as in the double basket, avoiding a change in shot time or grinder setting after switching baskets. In practice, well. . . .

I don't get what you mean. I don't think the surface area reduces by 50%. IOW reducing the weight by 50% does not correspond to a similar reduction in surface area through which the water must pass. Am I missing something here?