Crust in Aeropress

Coffee preparation techniques besides espresso like pourover.
5cylinders

#1: Post by 5cylinders »

Recently I have settled on using Aeropress in hybrid method. Instead of inserting plunger right after pouring to stop the dripping , I do it at 1:00, press at 2:30 (sometimes at 3:00). The cup is not bad to me.
The problem is : Aeropress forms a very deep crust. I'm not sure how it affect extraction and what I can to with it. I take some tests, stiring immediately after pouring, at 1:00 right before inserting plunger, right before pressing, 30 seconds before pressing, or simply ignore it. The results are inconsistent, now I'm comfused even more.
Any help would be greatly appreciated.
Thanks.

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drgary
Team HB

#2: Post by drgary »

I think you're making it too complicated. Basic Aeropress technique yields excellent and consistent extractions. I measure a n Aeropress scoop of beans, grind them a bit coarser than for espresso, fill the Aeropress plunger full of water that I heat to the desired temperature in a Bonavita kettle, pour the water on the grounds, stir to mix and insert the plunger to seal. After 30 seconds I remove the plunger, stir the coffee, reinsert the plunger and gently press through.

Change one variable at a time until you dial in getting a good extraction.
Gary
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What I WOULD do for a good cup of coffee!

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5cylinders (original poster)

#3: Post by 5cylinders (original poster) »

Thank you for the advice.
I agree with you in terms of flavour. However, for me, brewing coffee is not all about the cup, it's a more like a hobby, a toy to play. I guess that's the real "problem".

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drgary
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#4: Post by drgary »

That's different. Where are your results inconsistent when you expect consistency?
Gary
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What I WOULD do for a good cup of coffee!

millmountain
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#5: Post by millmountain »

5cylinders wrote:The problem is : Aeropress forms a very deep crust. I'm not sure how it affect extraction and what I can to with it.
I think it's good to establish a baseline for yourself. If you want a recommendation, follow a reasonable, well-documented recipe like the following:
https://aeroprecipe.com/recipes/tim-wendelboe

In the video, Tim discusses the influence of stirring, which relates to breaking up the thick layer of grinds. After pouring the water, "I stir three times, just to mix the coffee." This technique doesn't really have a bloom phase per se. Then at the end of one minute, again only three times. He explains, "...only three times back to front, because if we stir more or less we will change the extraction, so if we stir five times it'll be over extracted, if you stir one time it'll be under extracted, so it's important that we do it exactly the same amount of times every time."

This recipe and technique gives me good results even with unfiltered water and a substandard grinder, but there are two things about it I don't like. One is that it doesn't have a bloom phase. The other is that I prefer the inverted position, because of drainage: paper filters drain less, whereas I like being able to choose a disc instead, and I don't like having to stick the plunger in, because inevitably I don't do it fast enough or I push it in too far or don't get the seal right. (In other words, I need to train to get consistent.) So I recommend to also try playing around with methods that use an inverted Aeropress.

For a very long time I followed a recipe using the inverted position, prewarming the press (and then pouring out into the cup to prewarm it as well), pouring a small amount over the grinds and giving a quick stir for a 30s bloom phase, then filling the rest, giving a quick stir, and waiting to the 90s (which includes the 30s bloom time) mark to flip and push through during 30s.

Whatever technique you use, its versatility is the awesome thing about the Aeropress. Just be careful to think about and document about all details in order to get consistency.

5cylinders (original poster)

#6: Post by 5cylinders (original poster) »

drgary wrote:That's different. Where are your results inconsistent when you expect consistency?
The stir itself leads to inconsistency. I wonder there's a better way to deal with the crust.

5cylinders (original poster)

#7: Post by 5cylinders (original poster) »

millmountain wrote:I think it's good to establish a baseline for yourself. If you want a recommendation, follow a reasonable, well-documented recipe like the following:
https://aeroprecipe.com/recipes/tim-wendelboe

In the video, Tim discusses the influence of stirring, which relates to breaking up the thick layer of grinds. After pouring the water, "I stir three times, just to mix the coffee." This technique doesn't really have a bloom phase per se. Then at the end of one minute, again only three times. He explains, "...only three times back to front, because if we stir more or less we will change the extraction, so if we stir five times it'll be over extracted, if you stir one time it'll be under extracted, so it's important that we do it exactly the same amount of times every time."

This recipe and technique gives me good results even with unfiltered water and a substandard grinder, but there are two things about it I don't like. One is that it doesn't have a bloom phase. The other is that I prefer the inverted position, because of drainage: paper filters drain less, whereas I like being able to choose a disc instead, and I don't like having to stick the plunger in, because inevitably I don't do it fast enough or I push it in too far or don't get the seal right. (In other words, I need to train to get consistent.) So I recommend to also try playing around with methods that use an inverted Aeropress.

For a very long time I followed a recipe using the inverted position, prewarming the press (and then pouring out into the cup to prewarm it as well), pouring a small amount over the grinds and giving a quick stir for a 30s bloom phase, then filling the rest, giving a quick stir, and waiting to the 90s (which includes the 30s bloom time) mark to flip and push through during 30s.

Whatever technique you use, its versatility is the awesome thing about the Aeropress. Just be careful to think about and document about all details in order to get consistency.
Very very helpful. Thanks.
I also found this : https://www.baristahustle.com/blog/if-a ... developed/ and this : https://www.baristahustle.com/research- ... xperiment/

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drgary
Team HB

#8: Post by drgary »

5cylinders wrote:The stir itself leads to inconsistency. I wonder there's a better way to deal with the crust.
I believe the opposite is true. Stirring should cause a more even extraction.

BTW the person who taught me to stir was Alan Adler, the AeroPress inventor.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

millmountain
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#9: Post by millmountain »

Gary, maybe 5cylinders's conclusion, "the stir itself leads to inconsistency," means that performing the stir inconsistently produces inconsistent results.
5cylinders wrote:Very very helpful. Thanks.
I also found this : https://www.baristahustle.com/blog/if-a ... developed/ and this : https://www.baristahustle.com/research- ... xperiment/
Those look like great articles, I will read them.

Here is some food for thought on the crust and extraction. The crust forms because of CO2. This is similar to top fermentation in beer brewing. Certain yeasts produce CO2 and alcohol from the wort in a way that cause it to float. With coffee, as hot water comes into contact with the grinds, CO2 in the grinds gets freed. Darker roast levels of coffee beans tend to have more CO2, and the CO2 in fresh roast has had less time to dissipate, so some coffees produce a lot of CO2 quickly. The CO2 is less dense than water, so it lifts the grinds to the top, forming the crust. Because the grinds are surrounded by other grinds and CO2, there is less contact with water and the water that is present around the grinds increases its concentration of extracted coffee, which also slows the extraction. So the timing and degree of agitation definitely affects extraction, and its should be done in a consistent way for a given coffee. This is why we normally use a bloom phase, to get the CO2 out of the way during the rest of the extraction, and why I usually prefer an inverted Aeropress where I can more easily control a bloom phase without fiddling about drainage.

lukehk
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#10: Post by lukehk »

I use Michael Fabian's method with a 4 minute steep. Produces results similar to a cupping but this recent blog from Jonathan Gagne looks interesting https://coffeeadastra.com/2021/09/07/re ... aeropress/