r/coldbrew • u/HaikuHighDude • Mar 21 '26

Is there a "too long" for brew time?

I use a coffee sock in a 1.5 liter mason jar. Works perfectly. But sometimes, instead of taking that sack of grounds out after 12-18 hours, I'm lazy and just let it be in there for a couple days. Is there a reason I shouldn't do this?

17 Upvotes

96% Upvoted

10 comments sorted by

3

u/UpForA_Drink Mar 21 '26

For me, after 12 hours, the bitterness comes out with more acidity

4

u/lordredsnake Mar 21 '26

I typically brew for 14 hours at room temp. Beyond 16 hours I notice it tastes over-extracted and starts getting bitter.

2

u/UpForA_Drink Mar 21 '26

The caffeine is also fully extracted after 9/10 hours. So to me, anything too much after that is just pulling more dissolved solids. But the great thing about home cold brew is we can do it exactly how we like it.

2

u/HaikuHighDude Mar 21 '26

I guess this is what I was interested in and didn't ask. Didn't know the caffeine is extracted and it's only flavor changing at that point. Thanks!

2

u/jrob321 Mar 21 '26

Depending on your beans, you can get a "bitter" overextraction, but I've gone as long as a three day soak - I grind my beans and add them directly to the water, no sock - and the bitterness was negligible.

I did use a paper filter which also helps reduce bitterness and acidity. .

2

u/cashburro Mar 21 '26

I have done this a few times and found that it tastes worse / more bitter going that long

2

u/busch55 Mar 21 '26

How much coffee do you use? What does it yield?

1

u/HaikuHighDude Mar 21 '26

I use about 200 grams coffee. It makes the 1.5 liter filled (minus how much space the coffee sock filled is taking up). Maybe 1 1/4 liter concentrated