I have been doing some research on the history of espresso machines and the earliest known examples were all steam-powered and could only produce something like 1.5 bar which got me thinking that sounds like the pressure from an Aeropress. So I wonder how similar an Aeropress is to these early machines and if it produces something that might taste very much as a shot pulled back then. These early machines like the famous poster art of Victoria Arduino are verticle boilers of large cylinder-shapes and in shape alone not much different to the Aeropress (of course the Aeropress is a lot smaller). it makes me want to get a little cap for the Aeropress with an eagle on it.

Roughly 4 sq.in. area at 15-25 psi is 60-100 lb-f on the piston. That seems a lot higher than what most people would exert on an Aeropress, short of standing on it.

Temperature profile of the Aeropress is probably different too. Maybe a moka pot is a closer cousin.

Jeff wrote:Roughly 4 sq.in. area at 15-25 psi is 60-100 lb-f on the piston. That seems a lot higher than what most people would exert on an Aeropress, short of standing on it.

perhaps with the assistance of a lever.... but then it's a lever machine which isn't early 20th century (the topic is supposed to say 20th century)

Hoffmann had a Gabór-supplied pressure sensor installed in an Aeropress. He was able to hit 1.3 bar in his video and said he'd managed about 1.5. But you can see him really leaning into it. And when you push hard you open up the pores in the paper filter and end up with a cloudy drink. A more typical pressure is under half a bar. If you push with 10 lbs of force it works out to about 0.2 bar.

There was a guy who put his Aeropress under a juice press and theoretically hit something above 6 bar. He didn't actually measure the pressure and admitted that his Aeropress was venting around the seal during the press.

DamianWarS wrote:perhaps with the assistance of a lever.... but then it's a lever machine which isn't early 20th century (the topic is supposed to say 20th century)

The Aeropress isn't 20th century either.

I'm refering to the likeness of the coffee with an early 20th century espresso machine because both use a relative low pressure. The aeropress of course is early 21st century which is a bit of the irony. However this may only be the case with very specific conditions with the aeropress and perhaps other aids like a lever but earliest levers appear mid 20th century and of course produce much higher pressure than these early steam pressurized machines.

jpender wrote:Hoffmann had a Gabór-supplied pressure sensor installed in an Aeropress. He was able to hit 1.3 bar in his video and said he'd managed about 1.5. But you can see him really leaning into it. And when you push hard you open up the pores in the paper filter and end up with a cloudy drink. A more typical pressure is under half a bar. If you push with 10 lbs of force it works out to about 0.2 bar.

There was a guy who put his Aeropress under a juice press and theoretically hit something above 6 bar. He didn't actually measure the pressure and admitted that his Aeropress was venting around the seal during the press.

It would have to be a metal filter, fine grind and possibly a prismo or joepresso (joepresso probably better candidate but it has its own setup) If JH could achieve 1.5 bar than it seems at least plausible with the right technique of applied force or stronger individual to produce a pressure akin to these early espresso machines.

Using a lever of course you can achieve much higher pressures and the longer the lever the higher the pressure but I'm only taking about 1.5 bar which seems doable albeit perhaps at the high end without the aid of a lever. On top of that to really proove this idea you would have to blind test this theoretical 1.5 bar aeropress along with a 1.5 bar antique or remade early 20th century espresso. The latter may be harder to produce than the former.

Yes, you can apply the 60-90 pounds of force to an Aeropress to achieve 1-1.5 bar. It's doable. It's just not what almost anybody thinks of as "the pressure from an Aeropress".

so then the question is, does the coffee using that window of pressure produce something akin to an early 20th-century espresso machine? these early machines used steam to produce pressure and the resulting pressure was a lot less. Steam wands produce about 1.5-2 bar pressure so it might be just the safe operating level of pressurized steam. There was no crema in these earlier machines which is something that was discovered by higher pressure lever machines and a reason why crema to this day is regarded as a quintessential part of modern espresso. I'm not an advocate of this method of an Aeropress but I find it interesting to read comments that refer to attempts at higher pressures with the Aeropress as fake espresso which in fact it seems possible to be closer to an espresso made upon the early development of the drink which seems to be good enough to call espresso, albeit a low-pressure early 20th-century espresso.