Can crush lead to astringency

[olotti]

My last two batches both neipas have had a really back tongue sting/harsh astringency that is something I’ve never had and to take hop burn out of the equation this last batch I used even less hops and did a soft crash before the second dh. Coincidentally their the first two batches I’ve milled with my new kegco 3 roll mill, the gap is set at .28. In both batches, same grain bill, with Pilsner base, wheat, oats, c10 and carapils are mashed in at 1.65/qts per lb for 90 min then batch sparged with 4 gal at 195 to bring the grain bed to 168deg give or take for 7.5gal pre boil then boil to 6 gal. Could the astringency be from the crush and sparge or poss my compromised mlt which there is another post about that.

 

[Jtvann]

I've read, and its arguable by many as to whether its true, that crush can lead to astringency.

I believe it has more to do with extracting tannins. This is easier with a finer crush. Again, my beliefs and am open to an education. Things that affect tannin extraction are water temps above 170 and low pH.

With biab, as long as you aren't sparging with super hot water, or sparging at all ... or mashing out, then theoretically crush shouldnt matter.

 

[olotti]

So I hear my strike water to 175 to pre hear the mlt then add my grains and stir down to 154 mash temp. I then do a single sparge with 3-4 gal of 195 deg water to get The grain bed up to 165-168 then wait and drain my final runnings. My lhbs was using .34 on their mill the batches I’ve crushed ate at .28. See anything here that could be causing poss tannin extraction???

 

[RM-MN]

So I hear my strike water to 175 to pre hear the mlt then add my grains and stir down to 154 mash temp. I then do a single sparge with 3-4 gal of 195 deg water to get The grain bed up to 165-168 then wait and drain my final runnings. My lhbs was using .34 on their mill the batches I’ve crushed ate at .28. See anything here that could be causing poss tannin extraction???

Two items. Any time you have grains in a high temperature (above 170 approximately) and a pH of over 6.0 you extract tannins. You have two opportunities for this, one when you add the grains and one when you sparge. I'll make the assumption that when you add the grains to the 175 degree water they are cool enough to quickly pull the water temperature down below 170. Unless you add them slowly this would be the case. The sparge could be the culprit. If your pH is low enough the high temp wouldn't matter but we don't know the pH. There is no reason to sparge with that hot of water for a batch sparge, cool water works nearly the same without the chance of tannin extraction. Try a batch with the cool water and see if it solves the problem.

I do BIAB and my grains are milled to nearly flour consistency and I triple sparge, a distinct no-no as that can allow the pH to rise too high but I use water right from the tap so it is cool. No astringency with that approach.

 

[olotti]

Two items. Any time you have grains in a high temperature (above 170 approximately) and a pH of over 6.0 you extract tannins. You have two opportunities for this, one when you add the grains and one when you sparge. I'll make the assumption that when you add the grains to the 175 degree water they are cool enough to quickly pull the water temperature down below 170. Unless you add them slowly this would be the case. The sparge could be the culprit. If your pH is low enough the high temp wouldn't matter but we don't know the pH. There is no reason to sparge with that hot of water for a batch sparge, cool water works nearly the same without the chance of tannin extraction. Try a batch with the cool water and see if it solves the problem.

I do BIAB and my grains are milled to nearly flour consistency and I triple sparge, a distinct no-no as that can allow the pH to rise too high but I use water right from the tap so it is cool. No astringency with that approach.

I’ve considered the cooler sparge method. When I do mine now the grain bed is typically in the 130’s-140 range so after adding the sparge and stirring I’ve never had the temp over 170 the temps balance into the 165-170 range pretty fast. Not that this couldn’t be leeching a touch of astringency I think the real culprit For my main off flavor was a breech in the wall of my cooler and spoiled wort from previous batches was getting mixed in causing a very acrid astringent taste.