5 ms·

What kind of pressure are we taking about? This project would definetely benefit with chating with a barista and understanding the principle of brewing a coffe

What kind of pressure are we taking about? This project would definetely benefit with chating with a barista and understanding the principle of brewing a coffe shot, or working/getting experience with a professional machine. Personally i think the best you can get at home (unless you can afford a pro machine) is aeropress. Dead serious

ubermonkey 4y ago
>Personally i think the best you can get at home (unless you can afford a pro machine) is aeropress. Dead serious Given the notoriously grainy mouth feel of aeropress coffee, and the sheer joy I've had out of proper espresso made with even less-expensive home machines (e.g. a Rancillo Silvia, to say nothing of nicer home machines like Rockets), I'm utterly stunned by the weirdness of this assertion. I wouldn't be more puzzled if you'd said the best you can do at home is a Mr Coffee. Dead serious.
- quijoteuniv 4y ago
  Interesting, can you describe what is for you a good espresso shot?
  - ubermonkey 4y ago
    There's a certain sweetness that comes through with a well done shot, along with a real smoothness on the palette without sacrificing body. Certainly all coffee has a bit of bitter going on, but with a properly done shot -- under real pressure, with a dialed in set of variables (grind mass, desired shot mass, shot time, etc) -- it's just part of the party, not the whole thing. And you can absolutely get this at home, but you need a proper machine. (A Moka pot won't do it. People might LIKE Moka coffee -- lots do! -- but it's not the same thing.) I'd rather pull a shot from my Rocket than go to any shop in town. And, as I said, I've had shots just as good from machines much cheaper than my R58 (like the aforementioned Silvia). IME, genuinely good espresso is a fairly rare thing. The set of coffeeshops that pull consistently good shots is a much, much smaller subset of [Coffeeshops] than we might expect. What an aeropress produces is more akin to French press than anything else I've had. It's absolutely nothing like espresso. Since I'm not a French press fan, I end up not caring for it, but that's a preference thing, not an indictment of the method. When it comes to filter coffee (which is to say, non-espresso), I prefer Chemex.
qbasic_forever 4y ago
Espresso is typically made with 9 bar of pressure. An aeropress doesn't actually generate any pressure. It just moves a column of water through a puck of coffee like a percolator. You can buy some special add-ons for the aeropress that cause it to build pressure but it's really just for generating more foamy/crema brew and not getting a proper espresso shot out of it. All that said the aeropress is still awesome and a great way to brew coffee, it's just not going to replicate espresso shots.
- BlandDuck 4y ago
  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?
  - anon84873628 4y ago
    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.
  - DoubleFree 4y ago
    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.
    - klausa 4y ago
      Getting over 1 bar gets you to a spray of coffee that sprays everywhere: https://youtu.be/Qz_GZpzpst4?t=500 https://youtu.be/Qz_GZpzpst4?t=500
      - dmonitor 4y ago
        why does he have it so far away from the cup?
pmarcelll 4y ago
Pressure is not an issue since a vibratory pump in the most basic espresso machine can produce 15 bar of pressure quite easily. In fact, manufacturers have to put an overpressure valve in their machines to limit maximum pressure to the optimal 9 bar. Also, this project is about sophisticated temperature and pressure/flow control, something even many/most professional machines simply can't do. So I really don't think the person who built this machine lacks experience in brewing coffee.
- andrewxdiamond 4y ago
  Pressure is resistance to flow. In the aeropress, the coffee and the plastic filter screen resist flow and thus create pressure. Not very much pressure, but there is pressure
falsenapkin 4y ago
How do you know this person hasn't had plenty of relevant experience? And no hard disagree on aeropress. You can make great espresso at the correct temperature/pressure with non-pro machines. I make a few a week with a Flair Pro 2 and they're very consistent. Like <$700 for lever+grinder+kettle. I also have an aeropress and it's fine but they make different drinks.

ubermonkey 4y ago

>Personally i think the best you can get at home (unless you can afford a pro machine) is aeropress. Dead serious Given the notoriously grainy mouth feel of aeropress coffee, and the sheer joy I've had out of proper espresso made with even less-expensive home machines (e.g. a Rancillo Silvia, to say nothing of nicer home machines like Rockets), I'm utterly stunned by the weirdness of this assertion. I wouldn't be more puzzled if you'd said the best you can do at home is a Mr Coffee. Dead serious.

quijoteuniv 4y ago
Interesting, can you describe what is for you a good espresso shot?
- ubermonkey 4y ago
  There's a certain sweetness that comes through with a well done shot, along with a real smoothness on the palette without sacrificing body. Certainly all coffee has a bit of bitter going on, but with a properly done shot -- under real pressure, with a dialed in set of variables (grind mass, desired shot mass, shot time, etc) -- it's just part of the party, not the whole thing. And you can absolutely get this at home, but you need a proper machine. (A Moka pot won't do it. People might LIKE Moka coffee -- lots do! -- but it's not the same thing.) I'd rather pull a shot from my Rocket than go to any shop in town. And, as I said, I've had shots just as good from machines much cheaper than my R58 (like the aforementioned Silvia). IME, genuinely good espresso is a fairly rare thing. The set of coffeeshops that pull consistently good shots is a much, much smaller subset of [Coffeeshops] than we might expect. What an aeropress produces is more akin to French press than anything else I've had. It's absolutely nothing like espresso. Since I'm not a French press fan, I end up not caring for it, but that's a preference thing, not an indictment of the method. When it comes to filter coffee (which is to say, non-espresso), I prefer Chemex.

qbasic_forever 4y ago

Espresso is typically made with 9 bar of pressure. An aeropress doesn't actually generate any pressure. It just moves a column of water through a puck of coffee like a percolator. You can buy some special add-ons for the aeropress that cause it to build pressure but it's really just for generating more foamy/crema brew and not getting a proper espresso shot out of it. All that said the aeropress is still awesome and a great way to brew coffee, it's just not going to replicate espresso shots.

BlandDuck 4y ago
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?
- anon84873628 4y ago
  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.
- DoubleFree 4y ago
  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.
  - klausa 4y ago
    Getting over 1 bar gets you to a spray of coffee that sprays everywhere: https://youtu.be/Qz_GZpzpst4?t=500 https://youtu.be/Qz_GZpzpst4?t=500
    - dmonitor 4y ago
      why does he have it so far away from the cup?

pmarcelll 4y ago

Pressure is not an issue since a vibratory pump in the most basic espresso machine can produce 15 bar of pressure quite easily. In fact, manufacturers have to put an overpressure valve in their machines to limit maximum pressure to the optimal 9 bar. Also, this project is about sophisticated temperature and pressure/flow control, something even many/most professional machines simply can't do. So I really don't think the person who built this machine lacks experience in brewing coffee.

andrewxdiamond 4y ago
Pressure is resistance to flow. In the aeropress, the coffee and the plastic filter screen resist flow and thus create pressure. Not very much pressure, but there is pressure

falsenapkin 4y ago

How do you know this person hasn't had plenty of relevant experience? And no hard disagree on aeropress. You can make great espresso at the correct temperature/pressure with non-pro machines. I make a few a week with a Flair Pro 2 and they're very consistent. Like <$700 for lever+grinder+kettle. I also have an aeropress and it's fine but they make different drinks.