coffeebirds Senior Member Joined: 23 Dec 2012 Posts: 1 Location: USA Expertise: I love coffee
Posted Sun Dec 23, 2012, 8:16am Subject: Re: Aeropress - Hypothesis: Why it can't make "espresso"
I don't know about the strength of espresso, since I don't have any type of quantifying device, but I made some coffee with the Aeropress that tasted JUST LIKE ESPRESSO.
If you all know the basic concept of espresso, it is to draw plain water through pressed grounds that have been compacted with 30lbs of pressure. I did an espresso grind, compacted it with the aeropress itself (it wasn't a cohesive puck, but it was compacted). Then I put 2 paper filters of top of the grounds to separate the water from the coffee before I started pressing. Then I made like a syringe and pressed with a good amount of force. And out came coffee that tasted just like espresso.
The trick is to not use the Aeropress concept. Just emulate the mechanism by which real espresso is made. :)
Posted Sun Dec 23, 2012, 11:04am Subject: Re: Aeropress - Hypothesis: Why it can't make "espresso"
coffeebirds Said:
I don't know about the strength of espresso, since I don't have any type of quantifying device, but I made some coffee with the Aeropress that tasted JUST LIKE ESPRESSO.
I would question your experience with tasting espresso. "Real," high-quality espresso has body, mouthfeel, depth of flavor, and a lingering of tastes on the palate that surpasses the Aeropress coffee by a long shot. Dollar-for dollar it makes the best coffee around (IMO) but it isn't an espresso maker, the hyperbole on the device's packaging aside. I have told Alan, the inventor, this. I do like the device, and have seen him (as so many have) going around the SCAA show floor testing espresso with his refractometer (I think that is what it is), but espresso is best tested by drinking it. IMO, it's a case where science just goes so far and is somewhat out of place, or the findings misused regardless as to how accurate the findings may be.
The trick is to not use the Aeropress concept. Just emulate the mechanism by which real espresso is made. :)
So, how? Jack up the Miata and lower the left-rear wheel onto the plunger of the Aeropress? :-O
And resurrecting a thread after some 20 months - well done! ;-)
Posted Sun Dec 23, 2012, 4:44pm Subject: Re: Aeropress - Hypothesis: Why it can't make "espresso"
Actually, the real reason (with much more knowledge from when I first started this thread) is that the AeroPress is an IMMERSION method, whereas espresso is a high flow gradient low volume percolation method of brewing.
The math between the two methods just won't work out to the same thing.
A classic double ristretto can be thought of as 20% extraction of 14g of coffee, accomplished with approximately 8bar pressure, and yielding approximately 28g of beverage.
The simple yield math that works here:
14g * 20% = 2.8g TDS in the cup
2.8gTDS / 28g total beverage = 10% strength.
The goal with the AeroPress would be to produce 28g of beverage at 10% strength using 14g of coffee. Except there is no math solution that can do this using immersion brewing in a single step.
The average "assimilation" (a parameter that describes the increase in mass of the coffee grounds when wet at the end of the brewing cycle) is 1.2 or so.
At the end of an AeroPress brewing cycle, you need 28g of produced beverage, and the total mass of the beverage and the wet spent puck to weigh the following:
28g + 1.2X14 = 44.8g
So, the total of your brew water and coffee at the start of brewing (assuming no evaporation losses) must equal 44.8g, meaning the amount of brew water you would need to use is 30.8g (call it 32g and assume you'll lose 1.2g to evaporation).
This is an immersion method calculation where the Water Brew Ratio R=30.8/14=2.2
and the "effective extraction" for the system that predicts the end strength for an assumed 20% extraction is given by:
It isn't fair to updose to get the strength up - that is just playing games with the brew ratio. It's "cheating".
The bottom line is you can't get 20% extraction and achieve 10% strength and yield 28g of beverage with the AeroPress from 14g of coffee.
This is because the strength of the coffee in the puck for espresso is 1/3 or less of the stuff in the demitasse. The strength of the coffee in the wet grounds at the end of an AeroPress is the same as the stuff in the cup.
Now, is there a way to do this? Well, closer anyway. It's called "staged brewing". You can take 14g of coffee, finely ground, and put it in your aeropress. Heat up 35g of boiling water. Then, add 10g of hot water to wet the grounds. Count to 10. Then withdraw the plunger, add another 5 grams of water and press. DO NOT STIR. You'll get a few drops. Then repeat in 5g increments until you get around 30ml of coffee (if you can see it) fairly quickly. Press VERY hard at the end (you're looking to get every drop), and try and keep the water temperature essentially at boiling before drawing and pressing. You'll do this in about 5-6 presses.
You'll get something APPROACHING 10% strength, and it will taste a lot like espresso, but it will still not be espresso. It will calculate extraction properly, and it will be very strong, and it will start to have some of the flavor of espresso, but it will not be espresso.
And, you'll have gone to a lot of trouble to find this out.
Staged brewing works really well, you can use it to make nicely extracted cold or room-temp brewed coffee at decent strength. It's a bit of a pain, but one example of the games you can play with the brewing process once you understand it.
I've also played around with turning my AeroPress into a column percolation brewer with encouraging results.
The stuff you make from the AeroPress is really great concentrated coffee - awesome for recipes, ice cream, and lattes/AeroCaps, etc. But sorry, it's still not espresso.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
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