BIAB Sparge / Mash Out time

[jjones17]

Howdy! I was wondering what anyone else felt about the sparge /mashout time of BIAB method. I have always used to mash out /sparge at about 170 for 5 minutes. Recently, I have increased to 15-20. However, the last IPA batch I noticed has a tiny bit of astringency. I wonder if this is from tannins frmo my Sparge /MAsh out being too long?
Thoughts?

 

[Danek]

I've been meaning to post something on this, as I've encountered something kind of similar (though perhaps a little more extreme than your issue). I've made half a dozen BIAB beers, all of which turned out fine or better, so I'm happy that the method works and makes good beer. However, last year I made a Strong Dark Belgian using the BIAB method, and to try to maximise efficiency, after I took the bag out of the mash kettle (or whatever you call the big pot you use in BIAB!) I put the grain bag in an ale pail and sparged by pouring two or three pots of 170F water over it. I then added the sparge-water back to the big pot and started the boil. After the beer was fermented and bottled, it had a really nasty flavor to it - the closest description I can think of for it is to describe it as a kind of astringency. It was sufficiently unpleasant that I thought it must have been some kind of infection, but no description I've found of infections fitted that taste. It was the only BIAB beer I'd done that with, so I presume something nasty must have been extracted when I sparged the grains.

To test that theory, when I made a BIAB IPA last month, I sparged again but this time kept the sparge-water separate, and used it to make a small partigyle pale ale. If sparging a BIAB beer imparts nasty flavors, then the (unsparged) IPA should be fine, and the (sparged) pale ale should suck ass. I bottled both beers about three weeks ago, so over the weekend I'll taste them and see whether my BIAB sparging imparts unpleasant flavors. I'd be slightly surprised if it does, as I can't think why BIAB would be more prone to extracting tannins or other undesirables than regular mashing. But it is a (relatively) new method, so there may be BIAB-specific differences yet to emerge. If anyone else has had similar experiences it'd be good to hear about them. And equally, if people have BIAB-sparged with no problems at all, that'd be good to know too.

 

[jjones17]

I would be VERY interested to hear the results of your experiment. I have always done a sparge, however only the last few batches I have increased both the time, and the temperature. I used to just give up when I could not hit 170, and settle for 166 or so, for 10 mins. Then I got anal, and kept some boiling water on hand to bring up to temp. I always thought astringent tanins were really just a non-issue in home brewing, like worrying about something you needn't worry about. I think I will switch back to the slightly lower temp, and shorten the time. After all, I never really noticed a jump in efficiency.

 

[dcp27]

If you're worried about getting astrigency from the sparge, just lower your sparge temperature. There's really no need for it to be 170F.

 

[Danek]

...if sparging a BIAB beer imparts nasty flavors, then the (unsparged) IPA should be fine, and the (sparged) pale ale should suck ass. I bottled both beers about three weeks ago, so over the weekend I'll taste them and see whether my BIAB sparging imparts unpleasant flavors.

I've just tried these beers, and it turns out the beer I made just by sparging the BIAB grain bag is fine. (Well, it's actually a pretty mediocre beer, but there are no particular off-flavors to it.) So whatever problem I had last time doesn't seem to be attributable to BIAB sparging. Maybe the yeast was stressed. Anyway, there's nothing to see here. Carry on sparging.

 

[jjones17]

Thanks for the update, Danek. Good to hear as well. I have found a similarity in both my batches that had the astringency: Freshly Home roasted grains. Perhaps this is the cause? In both beers, I had roasted some grains to various levels but had not given them time to rest. Many recommend a week of rest after home roasting. Well, my last batch was using all home made Crystal malts (which were roasted to about 70L), and these grains had at least a week of rest. This batch had no astringency. I wonder if this is the cause?