another_jim wrote:30 lbs is the number Schomer came up with.
I'm confused how either of the two responses addresses the question?
Did Schomer come up with 30 lbs using a 58mm tamper? Does this mean a 53mm tamper should only use 26 pounds?
My point is that saying "30 lbs" seems ridiculous. 30 pounds of pressure over a basket the size of a garbage lid would be tremendously less than 30 pounds of pressure on grounds poured into a straw. Obviously those two extremes illustrate the point while being ridiculously outside the real range. However, there is a surface area difference between 53 and 58mm. If "30 lbs" is the answer for 58mm, then why is not 26 lbs the answer for 53mm baskets?
Coffee grounds (and anything else in the univers) react to pounds per square inch. Not to "pounds."
I guess I'm just confused on the whole theory.