I've been a batch sparger for many years, but after moving from propane to electric, the new rig can also fly sparge, so I've been trying that.

The first two beers came out with a permanent haze, despite using isinglass finings and cold conditioning, and there is a noticeable astringency - it tastes a bit like iced tea. I'm guessing I have oversparged - final runnings were 1.004 and the sparge liquor was 82C, which I now know to be way too high.

Is there anything I can do to improve the flavor or remove the tannins? The beer is a Bass ale clone, and London Pride clone.

Edit: as brewchez suggests, I'll be fixing my process - I've calibrated the RTDs so sparge temp should now be correct, and I've got a refractometer and pH meter to monitor the sparge. But is there anything I can do to improve these 20 gallons of beer? How about gelatin, will that strip out some tannins?

  • Maybe (and this is a pure guess) try filtering it through a 0.5 micron filter? I doubt it will be like what you are trying to clone, but it might remove some interfering substances and then you could "tweak" it with some adjuncts. Just an idea. I consider a ruined clone batch to be an opportunity to get creative. Jan 20, 2012 at 21:37
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    thanks for the tip. I have a filter, but not that grade - I have a 1 micron filter. Will that do? I used isinglass to fine, but I don't think that works against tannins.
    – mdma
    Jan 21, 2012 at 1:13
  • Honestly I don't know. I'm not even sure the various protiens from the oversparged husks can be filtered; I do know it will filter some stuff you don't want filtered. That's why I say it's a ruined clone batch, but may be salvageable as a "MDMA Original". Jan 21, 2012 at 16:07

3 Answers 3


Not really. Its best to focus your energy on fixing your process and brew again. Fixing a single beer is usually not effectively possible. Giving up one batch and fixing the process "fixes" all your future batches.

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    I don't fly sparge myself, but I've read that lowering the pH of the sparge water helps reduce tannin extraction. Jan 21, 2012 at 16:08
  • Good advice from brewchez. I'd say you should back to batch sparging, huh?
    – Denny Conn
    Jan 21, 2012 at 16:56
  • I agree it's good advice. It was my first fly sparge, and I kind of thought "how bad can it be?" and just let things take their course without too much intervention. I've a pH meter and refractometer so no reason other than laziness not to monitor the sparge more closely.
    – mdma
    Jan 21, 2012 at 17:55
  • @TobiasPatton pretty sure that the dropping pH of the mash while sparging is where tannin extraction comes from. So lowering your sparge water pH is probably not a good idea.
    – brewchez
    Jan 22, 2012 at 19:54
  • @brewchez - from the brewing material I've read, the sparge should stay below 5.8-6.0 to reduce tannin extraction. Initially it's around 5.2 after the mash, but eventually starts rising as the grains buffering capacity is diluted. I understand some brewers acidify their water if it's much above 7pH to help keep the sparge under 5.8. Also, reducing the temperature of the sparge liquor during the end of the sparge can also help - the lower temps don't affect lautering since most of the sugars are already rinsed. I will be doing both of these things next time!
    – mdma
    Jan 22, 2012 at 23:22

I agree with brewchez's comment about fixing the process, and that should be done to avoid recurrence of the problem. For me, I will go back to batch sparging. However, before dumping 10 gallons of tea-beer, I wanted to find out if I could remove some of the astringency. And it seems you can.

I used gelatin to clear the beer in one of the kegs, and left the other keg alone as a control. After a week, the astringency was greatly reduced in the gelatined keg, but not so in the other keg. The astringency is not 100% gone - it's there if you look for it - but it's below some of the other flavors. The beer is now enjoyable.

  • Wow very cool discover!! I've dumped a batch because of astringency before. That batch was pretty bad, tasted a bit like chalk, but now I wish I'd seen your suggestion before.
    – GHP
    Mar 5, 2012 at 18:21
  • Hmm something just occurred to me. Did your beer have a lot of Fuggles hops? I seem to recall a few beers with Fuggles being kind of papery & astringent, so much so that I've avoided that hop. If the gelatin had the effect of pulling the hop material out, then perhaps your off flavors are from the hop and not the mash pH.
    – GHP
    Mar 5, 2012 at 18:23
  • I had it happen on two different brews, one without any Fuggles and one with 1oz at flamout (10 gallon.) So not a lot of fuggles. Interesting suggestion though.
    – mdma
    Mar 5, 2012 at 19:11
  • Yeah ignore the Fuggles bit maybe. It could be any variety of hop. I have read that hop material in suspension in beer creates a "bitter-like" flavor which can be perceived as astringency. It seems likely to me that if gelatin fixed your problem, that something relatively large (like hop particles) is to blame rather than stuff too small or too diffused to be affected by gelatin (esters/phenols, fussels, proteins maybe, etc).
    – GHP
    Mar 5, 2012 at 21:19

Tanins bind to protein, and gelatin is derived from collagen which is a protein. It is logical that the addition of gelatin bound the tanins and deposited them in the trub.


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