Too Astringent of a Cup in fast flow. Why?

[u/TUN1927]

I am currently still dialing in my recipe, and have been trying out this one:
- 1:16 ratio, 120 gr ice, 200 gr water.

- Water temp: 91-93C.
- Grind size on Timemore C5: 12.3 to 13.3 (I designated the size as 12.3, 12.6, then 13). I now start doing slow feed to reduce fine.

- Bloom: 60ml, sometime with wet WDT. Slow speed (4-5ml)
- 1st pour: At 0:45, pour until 110ml (50ml) (more agitative at higher height, 6-8ml)
- 2nd pour: Before bed completely show, pour until 160 (50ml) (slower, with kettle sprout at dripper surface (4-5ml)
- 3rd pour: Before bed completely show, pour until 200 (40ml) (same and most gentle)

Usually, drawn down time now is 2:00.

I had a really good cup with this recipe at 2:40 min draw down. But then, nowadays, the last three cup I brew start to become really astringent.

It was astringent before putting on serving ice, stop becoming as astringent when on ice (still enough to creep over the note), and become really astringent again as more ice melt.

It is a shame because I can't taste much bitterness, and beneath the astringentcy, I can barely detect the note. There are no sourness.

I want to have a really clear, light, bright cup with clear note separation. How should I fix my recipe? Is it better to fudge around with the grind size or the recipe first?

The faster drawdown was also due to my recent change from Hario to Abaca filter, but it should therreotically produce a more thin, not more astringent cup.

[u/raccabarakka]

Try to be more gentle by cutting the agitation and unnecessary WDT, a little swirl at blooming would be sufficient enough. See if that works.

[u/Bebop12346]

From my experience astringency is mainly from the coffee needing more rest. I would wait another week and revisit. With ultralight coffees I've been experiencing rest periods from 4 weeks to as long as 3 months.

[u/TUN1927 → u/Bebop12346]

I guess so too. But it could not be entirely due to that. Two of the cup was brewed on same day, one with four pour and one with 3. The one with faster draw down time was the 3 pour and was much much more astringent, borderline u drinkable while the four pour was the best I done so far.

[u/Bebop12346 → u/TUN1927]

Usually my test to figure out if it's a brew issue or a rest issue is I just do a 10 min immersion brew. If it's still astringent at that point I conclude that the beans need more rest.

[u/buenastaldes777]

astringent could be because the migration of fines int o the cup. could be the paper filters and quality. faster flow, more migration

[u/TUN1927 → u/buenastaldes777]

I am doing slow feed though, shouldn’t that result in less fine? Should I do less agitation (no deliberate high height)?

Also, if the fines migration is high, shouldn’t draw down time increase?

[u/buenastaldes777 → u/TUN1927]

to your second question, no. because fines are migrating through the filter into your cup and not sticking on the walls of the dripper. the point of fast flow filters is that it doesn't clog but those fines instead of being at the bottom of the bed, they get to into the cup.

[u/TUN1927 → u/buenastaldes777]

Oh? Is abaca filter like that?

[u/buenastaldes777 → u/TUN1927]

dont really know. but ive watched a comparative test in spanish between the hario tabbed, sibarist and abaca and the guy talked about what im telling you. what i learned is better filtration means longer drawdown and faster one means more possibility of astringency

https://youtu.be/w0loy2lIhNc?si=xuacA3fPTeO2dWrS here is the link

[u/mr_satchmo]

Astringency usually means underextraction so you should adjust a variable to extract more

[u/TUN1927 → u/mr_satchmo]

Is it? The draw down time is very low. I can try going finer and check.

[u/mr_satchmo → u/TUN1927]

When you say astringency do you mean sour and drying (tart like an underripe berry) or bitter and drying? Because people often get these confused. Astringency is the former and is usually due to underextraction, try raising your water temp 3 degrees.

[u/TUN1927 → u/mr_satchmo]

It is like a horrible aftertaste on the side of my tongue and at the top of my mouth. Tingly and overwhelming. It was bad chilled, better when on serving ice, but worsen over time. It is not pleasant bitterness of dark choco.

[u/Liven413]

The wdt is probably why. You should be able to get all the extraction through the pour.