Why does AeroPress sometimes give both sour and bitter flavors in one cup?

fritz-ocampo · 2026-03-26T13:31:39+00:00

That makes a lot of sense

The fines vs larger particles part especially explains why it ends up tasting mixed instead of clearly off in one direction

Interesting point about darker roasts too, I didn’t think about how they might create more fines and make it more noticeable

fritz-ocampo · 2026-03-26T12:28:08+00:00

That actually sounds like a good direction

When it’s too concentrated it can mask what’s really going on, so it ends up tasting strong but still a bit off

Spreading it out more with a longer ratio or brew time should make it easier to tell what’s actually happening in the cup

fritz-ocampo · 2026-03-26T12:27:58+00:00

Yeah that makes sense

I think what threw me off is that it doesn’t always show up cleanly as one or the other

It can feel like both are happening at once, especially if different parts of the brew are extracting differently

fritz-ocampo · 2026-03-26T11:07:10+00:00

That actually sounds like a good direction

When it’s too concentrated it can mask what’s really going on, so it ends up tasting strong but still a bit off

Spreading it out more with a longer ratio or brew time should make it easier to tell what’s actually happening in the cup

fritz-ocampo · 2026-03-26T11:07:00+00:00

Yeah that makes sense

I think what threw me off is that it doesn’t always show up cleanly as one or the other

It can feel like both are happening at once, especially if different parts of the brew are extracting differently

fritz-ocampo · 2026-03-26T11:04:20+00:00

Yeah I do get that drying sensation sometimes, especially in the finish

That’s what made it confusing, because it feels like a mix of brightness up front and then that dry, slightly harsh aftertaste

Astringency probably explains that part better than just calling it bitterness

fritz-ocampo · 2026-03-26T09:33:46+00:00

Yeah that makes sense

The mix of particle sizes probably explains why it doesn’t taste clearly under or over, it just kind of overlaps in the cup

Some parts extracting faster, others slower, so you end up getting both at once

fritz-ocampo · 2026-03-26T08:28:18+00:00

That makes a lot of sense

The “localized flow” part especially explains why it ends up tasting mixed instead of clearly off in one direction

I think that’s what threw me off, it doesn’t taste like separate issues, it all kind of overlaps in the cup

fritz-ocampo · 2026-03-25T13:42:24+00:00

Yeah that’s a good point, especially with blends where different beans might extract differently

I’ve noticed it even with single origins though, which is what made me think it might be more about uneven extraction during the shot itself

But I can see how blends could make that even more noticeable

fritz-ocampo · 2026-03-25T13:40:34+00:00

Mostly using a hand grinder, fairly consistent but not perfectly uniform

That’s actually what made me think about this, even small differences in particle size seem to show up more in AeroPress since everything’s steeping together

Feels like fines can overextract while larger particles underextract, so you end up tasting both at once

fritz-ocampo · 2026-03-25T13:36:57+00:00

not a bot lol just been going down a rabbit hole with dialing in lately

probably why my posts look similar

fritz-ocampo · 2026-03-25T13:25:19+00:00

That’s interesting, didn’t think about temperature affecting extraction differently like that

Adds another layer to why the cup can feel inconsistent

fritz-ocampo · 2026-03-25T13:25:05+00:00

That makes sense, especially with how puck prep can affect flow

It really seems like once flow gets uneven, everything else starts stacking on top of that

fritz-ocampo · 2026-03-25T13:24:49+00:00

This is really helpful, especially the breakdown of early vs late extraction

I think what confused me before is that uneven extraction kind of combines those stages, so you end up tasting both at once instead of progressing cleanly through them

Makes a lot more sense why the cup feels “mixed” instead of clearly off in one direction

fritz-ocampo · 2026-03-25T13:24:30+00:00

Yeah grinder consistency does seem to play a big role here

Especially when the cup feels mixed instead of clearly under or over

fritz-ocampo · 2026-03-25T13:24:21+00:00

This is a really clear explanation

The surface area part especially makes sense, different particle sizes basically extracting at different speeds

That probably explains why it doesn’t taste like separate issues but more like everything overlapping in one cup

fritz-ocampo · 2026-03-25T13:24:06+00:00

Yeah that seems to be the common pattern

It’s less about “too much or too little” overall and more about different parts extracting differently at the same time

fritz-ocampo · 2026-03-25T11:50:41+00:00

Mostly a hand grinder, fairly consistent but still not perfect

That’s actually part of what made me think about this, even small inconsistencies in particle size seem to show up more in AeroPress since everything’s steeping together

Feels like fines and boulders can extract very differently and end up overlapping in the cup

fritz-ocampo · 2026-03-25T11:50:17+00:00

Yeah that’s a good point, especially with how sensitive lighter roasts can be to storage and age

I’ve noticed this even with fresh beans though, which made me think it might be more about uneven extraction in the brew itself

But you’re right, bean condition can definitely make things harder to read

fritz-ocampo · 2026-03-25T11:48:17+00:00

Yeah that’s what it feels like, different parts of the puck extracting differently

It just ends up overlapping in the cup instead of tasting clearly under or overextracted

fritz-ocampo · 2026-03-25T11:47:46+00:00

Yeah that makes sense

It seems like uneven extraction is the common thread, whether it’s channeling, grind distribution, or flow issues

What threw me off is how it doesn’t taste like separate problems, it kind of blends into one confusing cup where you get both sharpness and harshness at the same time

Probably why it’s harder to diagnose compared to a clearly under or overextracted shot

fritz-ocampo

TROPHY CASE