What am I screwing up in BIAB?

And efficiency can vary by recipe.
 
How are you losing that much wort to grain absorption? Loss should somewhere between .25 and .5 qt per lb. How big is your grain bill? I use a combo system with bag in a recirc tun and I pull and squeeze after sparge so I can eke out another couple quarts of good wort. For a typical mash on a pretty big grain bill, I'll lose as much as a gallon, but no more than that. My efficiency tends to be in the mid-high 70s.

PS...I just realized that you're almost certainly talking about post-boil volume. What's your pre-boil volume? If I start with 31 quarts for a 10 lb mash, I'll put as much as 28 quarts in the boil pot and boil down to 5.5 gallons into the fermenter over 1.5 hours. You may be able to control other losses and get better system efficiency.

Grain bill is normally 10-12lbs. I believe my last brew session starting volume was 9 gallon. Mash complete/pre-boil was 8.1. Boil complete 6.5. Transferred 5.5 to fermenter and just packaged 5.1 gallons.
 
Grain bill is normally 10-12lbs. I believe my last brew session starting volume was 9 gallon. Mash complete/pre-boil was 8.1. Boil complete 6.5. Transferred 5.5 to fermenter and just packaged 5.1 gallons.
Sounds pretty good, but I'd try to get more from the kettle to the fermenter. If you're throwing away a gallon of finished beer, it's going to wreck BH efficiency. Either start with less and keep everything else consistent or get a bigger fermenter. :)
 
I have a 6.5 gallon big mouth bubbler, so I think my fermenter is big enough. That gallon after boil is normally sediment at the bottom of the kettle. I may hVe some wort that’s not transferee but not a gallon worth. I don’t know.
 
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I always just put the whole kettle into the fermenter and let the protein sediment settle out after fermentation. It packs down tight under the yeast, you rack clean beer off and you end up increasing your yield as you retrieve probably 3/4 of what you would have left in the pot. I usually put 5.5 gallons in the fermenter, sludge and all, and get 5 gallons out.
Some argue against kettle trub/break material going into the fermenter, but there's nothing in there that will cause harm and it actually acts as yeast nutrient. Whatever works for you, but I've made consistently good beer that way. :)
 
I do the same and also I did some testing years ago and pulled the clear beer off the trub to add to the fermenter and it did not ferment well at all, you need some trub at least for amino acids and natural yeast nutrients
 
Yes...That!^^^ ;)
Pour it all in and stop dumping all that good beer out - too close to 20% to comfortably ignore. :)

OTOH...if you're throwing all your late kettle hops in loose, and then whirlpooling to separate the hop-gunk, maybe leaving some in the kettle isn't a bad idea. I use a bag specifically so I don't transfer hops to the fermenter (unless I want to do so for purposes of dry-hopping at yeast pitch).
 
I happen to like the BIAB method because it’s very simple and it takes a lot less cleanup. In line with keeping things simple, I prefer a dunk sparge over the other methods. You may want to view this YouTube video by Mash Hacks. In this video, he takes you through the whole BIAB process, including sparging by placing the bag of grain in a separate bucket, rinsing with water (starting at 6:25), stirring the mash, letting it sit for 5 or 10 minutes. He says that even cold water will do for the sparge, as it’s easier and safer than using hot water. He calls this the “second runnings.” He removes the bag from the bucket, then pours the second runnings into the brew pot, and raises the heat of the pot to boiling.

 
I mash in a coleman cooler with a brew bag so I end up with almost random efficiency but their point about trub is spot on. I haven't tried a BIAB brew but I'm trying to talk a friend that doesn't have much room into trying it.
 
I mash in a coleman cooler with a brew bag so I end up with almost random efficiency but their point about trub is spot on. I haven't tried a BIAB brew but I'm trying to talk a friend that doesn't have much room into trying it.
It's an interesting notion: Replace all that stuff in the cooler with a valve and a dip tube and let the bag manage the lauter. You wouldn't even have to lift the bag of wet grain, just batch sparge as usual. You insulate the mash to maintain temperature, you reduce the cost of the mash tun, you might even get a better lauter from the thin-mesh bag as opposed to the holes in a false bottom or a manifold, you can do everything the "all grain" way then you can just pull the bag of spent grain out later. Brilliant!
 
yes its been done for years, the only draw back is over time the cooler warps an needs to be replaced
 
I paid $20 for a 15 gallon cooler, I'm quite happy with it. I don't even put a dip tube in, I just have the valve but my brew bag is a little big so I end up lifting it to improve drainage.
 
I paid $20 for a 15 gallon cooler, I'm quite happy with it. I don't even put a dip tube in, I just have the valve but my brew bag is a little big so I end up lifting it to improve drainage.
Much simpler and likely works better than my false bottom setup. And to limit wort loss, just a piece of silicone tubing extending to the bottom would work fine, although I was thinking it would be better to pull the wort from the edge of the tun rather than the middle. For that, a simple elbow would work fine.
 
I only lose maybe 200ml to the bottom of the cooler right now.
 
I only lose maybe 200ml to the bottom of the cooler right now.
Seems acceptable. Losses would depend on how far the outlet was from the floor of the cooler.
 
I'm fine with it, the brew bag increases my efficiency significantly so I can afford the loss. The drain on mine is pretty low though.
 

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