Re:An Open-Source Espresso
by BlandDuck on Monday March 27, 2023 @03:43PM
(#35331376)
About the Aeropress, I guess the question is: When I press it down (in my case, using the elbow for added pressure) how many bars can a typical user reach?
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Re:An Open-Source Espresso
by DoubleFree on Monday March 27, 2023 @04:03PM
(#35331652)
Let's do a little calculation. For an upper bound, let's say you press your full weight onto it and the coffee grounds' resistance is not the limiting factor. That's maybe 90kg, times the acceleration of gravity, for about 900 newtons. That force is applied to a pi*(30mm)^2 or ~3^-3 m^2 area. That gives us a pressure of 900/3e-3 = 3e5 Pa or 3 bars.
Getting over 1 bar gets you to a spray of coffee that sprays everywhere: https://youtu.be/Qz_GZpzpst4?t=500
why does he have it so far away from the cup?
Hoffmann measured this with a pressure sensor modded aeropress - most typical brews would not exceed half a bar.
Re:An Open-Source Espresso
by anon84873628 on Monday March 27, 2023 @04:01PM
(#35331628)
Maybe 1 bar. You need a big lever or pump to get more than that. Check out the Flair or Wacoco brands if you want entry level manual espresso.
James Hoffmann answered this with a modded aeropress with a pressure sensor: a typical aeropress brew is in the range of half a bar. The max he could achieve was 1.5 bars, but like he says, no one brews like that. He also found anything past 0.5 bars began to taste awful.