Astringency Qs

I feel like I’ve had some astringency issues on my last few batches. Not bad, but enough to make me want to hunt down the cause(s). Recently, SWMBO presented me with a copy of Brew Chem 101 by L. Janson, PhD. I can’t quote him exactly because, well, I’m supposed to be working and he’s at home, but he says that one cause is the re-absorption of the kraeusen by the beer. He says that you should always use a blowoff tube so as to get as much of the kraeusen out of the carboy as possible, thus avoiding astringency.

Well I’m sorry, L. Janson PhD, but this set my BS detector off. If that were really true, I figured, then our discussions about kraeusen, blowoffs, yeast, and headspace would be much different. There would be enterprising souls marketing Kraeusen Skimmers™ and Tubulators (patent pending) to eager homebrewers. Is there any truth to what he is saying?

On a related note, Papazian offers the advice “do not oversparge”. Can someone explain this to me? How do you know when “enough” becomes “too much”?

Thank You!

That book is the worst brew-chem book ever published. It is full of errors
and should be banned!!

frazier said:

On a related note, Papazian offers the advice “do not oversparge”. Can someone explain this to me? How do you know when “enough” becomes “too much”?

Click to expand...

There's a few variables at play, including temp and pH, but the rule of thumb is, don't sparge below 1.010 to minimize tannin extraction.

The Krausen is the most active part of the fermentation... don't skim it unless you're looking to get just a little bit of yeast as a 'top crop'

Oversparging is simply running too much sparge water through your mash. The tannins wash out into your wort when you sparge too hot or try to extract too much sugar and the mash ph gets too high (remember, your ideal mash ph is 5.2-5.4) from your sparge water being more basic than the acidic mash (the grains make it acidic). I'm going to generalize here and say that most homebrewers experience a low enough efficiency (even at 75-80%) that they don't really wash the grains enough to get to that point without collecting too much wort for the boil. +1 to jkarp, easiest way to be sure is to not collect lower than 1010. I just don't worry about it that much... I don't even check to see if I'm below 1010 (I'm lazy).

What was the temp of your sparge?

I'm guessing that it's probably something in your fermenting process. What was your pitching temp? What was the temp for the first couple days?

I sometimes have astringency problems (assuming that is what I am, in fact, tasting). And they have always been in beers that had some amount of highly roasted malt (ie Pale Chocolate). I am assuming that it's a water chemistry problem on my end, but I don't have the water chem chops to figure it out. That's the "real" sciency part of brewing that I stay away from ....

For me, I solved it by (a) brewing beers without a lot of highly roasted malt (easy for me cause I don't care for Porters or Stouts really), and (b) using a fair bit of crystal malt if I do have some chocolate in there. I've done a SN Tumbler clone twice that's AWESOME: it uses 6oz of Pale Chocolate and a full pound of British Med. Crystal. Fuggin' delicious brown ale is the end product.