HB wrote:but I wonder if the heightened importance you place on precise dosing is directly related to the modest tamp.

no.

barry wrote:no.

why?

ken

because variations in dose result in variations in shot time, for any given grind. if one is inconsistent in dose, then one can often chase grinds settings and/or other variables, or blame other things (water temp variations, etc) in looking for reasons for differences in shots.

barry wrote:because variations in dose result in variations in shot time, for any given grind. if one is inconsistent in dose, then one can often chase grinds settings and/or other variables, or blame other things (water temp variations, etc) in looking for reasons for differences in shots.

I was just trying to force you to write a complete sentence.

ken

bastard.

barry wrote:because variations in dose result in variations in shot time, for any given grind.

No argument there. My (wholly unproven) assertion was that a small variation (say 0.5 grams) would negatively affect the extractions of no-tamp barista more than the barista tamping 30-40 pounds.

HB wrote:My (wholly unproven) assertion was that a small variation (say 0.5 grams) would negatively affect the extractions of no-tamp barista more than the barista tamping 30-40 pounds.

i don't see how it would matter.

barry wrote:i don't see how it would matter.

Truth be told, ground coffee is not really all that compressible. In my terribly humble opinion, tamping only matters for the brief period of time before the whole puck is saturated; it may effect, in combination with such things as pressure ramp up times/preinfusion, the likelihood of channeling, which of course will have a major impact on shot timing if it occurs.

Assuming no channeling, and a fully saturated puck, the mass of coffee in the PF is going to effect the timing of the shot from the very beginning to the very end.

I do think this is an onion that can be sliced all sorts of ways and it is hard to make blanket statements about the importance of any one aspect of it. If you find a technique that works for you on your equipment, and you are happy with the results, there is no reason to change. There will also be machine factors that will make some techniques successful on a given machine that might not work on others. And, there are modifications (such as the delay on make timer that Michael Teahan suggested I put in on my rotary) that impact this as well.

From a couple of weeks of daily use of the modified rotary, I can now state unequivocally that preinfusion, done in the way my machine has been modded to do, makes espressomaking easier and there are many fewer sink shots. This is to say that the system is now much more forgiving of barista technique errors and variation than before.

ken