My Efficiency Sucks

If possible, I'd recommend giving the grains a good thorough stirring when they're submerged prior to tying the bag off. It's very easy for the grains to form dough balls when confined.

 

Double up on some of your efforts, if you like. You can put half of your grains through the mill a second time. You can stir your grains a second time after 20 or 30 minutes of mashing.

 

Crush finer. For BIAB a "standard crush" is often not fine enough, and since you're not recirculating your wort in a mash tun, you don't have to worry about stuck run off. Try pulverizing it next time.

 

Sounds like your LHBS's mill needs help, or replaced. That mill should be able to destroy that grain bill in less than a minute! This is the reason I bought mt cerealkiller mill. Cheap, reliable, and I don't have to worry about other jack-off's playing around with settings, or trying to grind something they shouldn't.

PS: If you do change the settings on the mill, don't forget to put it back to where it was.

 

My guess is that the mesh of the bag you are using is too fine.

 

Half your recipe is wheat. Wheat kernels are smaller than barley kernels. If your grain mill is not crushing barley well, it is probably really not crushing the wheat at all. I usually get 70-75% efficiency, but batches with wheat have come in at 10-15% lower. You gotta beat your wheat.

 

I think this might be your problem. I've done BIAB twice now with roughly 75% efficiency each time, but the bag that I use is large enough that I can fold it over the top of my kettle and leave it open. This lets me stir the grain thoroughly at the start of the mash to get all the grain wet (and to keep the temperature even as the mash progresses). This was a cheapo 24"x24" bag that I got for about six bucks and it has been doing a great job so far.

 

This is good to know. I use BIAB, and with my first wheat beer yesterday, my efficiency was 10% lower than expected. I've been scratching my head but this makes sense.

Completely agree with this. I use the same size bag and secure around the outside of the pot with a bungee cord.

 

With 50% of the grain bill wheat the mash probably doesn't have the power to convert the starches to sugars. I learned after my first saison which had about %30 wheat that my efficiency suffered because of the mash ph. Now i use a small amount of acidulated malt when i use that much wheat to balance the mash ph, i get normal efficiency in those grain bills now.

 

Fact check:

Wheat can have a grain size comparable to 2 row depending on the variety of wheat.
Wheat can have a diastatic power comparable to 2 row depending on the variety of wheat.

 

Wheat malt has lots of diastatic power (i.e. enzymes).

If mash pH gets high enough, it can certainly affect mash efficiency. But I wouldn't portray that as a lack of power. It's a matter of taking (more than) adequate enzymes and putting them in an inhospitable environment. As you figured out, the answer was to acidify the malt, not to add more diastatic power. I think you know this, but I wanted to clarify for the OP.

 

I was thinking of the right idea of too high a mash ph, just the wrong wording. Thank you for clarifying VikeMan, I'm still working on the minutia of all this information.

 

Maybe it's a "hardness" factor? I definitely have seen lower efficiency with wheat in cases that I didn't specifically try to have it ground finer.

 

I'll accept your first fact but it is contradictory to my personal experience. I don't know why the op had problems with this batch or why I routinely see lower efficiency with wheat. My explanation above is the best hypothesis I have for my own experience with small wheat kernels; like most hypotheses, it serves as a placeholder until observations lead to a better one. Waiting.

 

And contradictory to this person's experience too: http://www.brewersfriend.com/2011/10/16/wheat-malt-in-all-grain-brewing/

 

Large kernel wheat is available. I use it and don't have efficiency issues with wheat.

 

OP, k'zoo tap water is moderately alkaline, so your pH might be high. One reason Bells makes tasty stouts and porters.