Lower efficiency when using wheat?

I have brewed quite a few batches using wheat lately and I have noticed my efficiency dropping, or rather my O.G.'s coming in 5-8 points below what I had expected. One was a India Pale Weizen, a Hefeweizen and a Wit.

I am looking at one or two possible issues:

  1. The recipes I used were generally imported from BeerSmith and the starting point was the Northern Brewer recipes. I would modify those recipes a bit but I notices that when I import like that, the brew house efficiencies and mash efficiencies do not seem to change when I change the profiles to mine. Again, I just sort of discovered and suspect this as an issue.

  2. I noticed that generally the wheat grain is much smaller “kernals” than barley. I have been weighing out my grain and mixing it all together before crushing in my Barley Crusher. Is it possible that I am not fully crushing the various wheats I have used because of the size and that this means I am not getting the full sugars out of them? In several of the beers, I have around 50% wheat.

Could be both. I do find that wheat malt seems a little smaller and thus needs to be crushed more finely than you might usually do. Tighten up your mill or double or triple crush and your efficiency will go up. I can get efficiencies in the 90s with wheat, rye, you name it. Just need to crush it well, and consider throwing in a handful of rice hulls if necessary due to the lack of husks to prevent a stuck runoff.

Agreed! Smaller kernels. Tighten up your gap or double crush. I get my grains crushed at my LHBS and always ask for a double crush when using wheat or rye. MY LHBS owner was actually the first to recommend this to me.

+1 here double crush

Good to know! I will start crushing the wheat and rye separately. My mill still has factory settings and makes a good crush so I hate messing with a good thing.

One of the home brew catalogs I have at home (N.B., William’s, or Morebeer) lists a white wheat that is larger and should work the same as barley going through the mill.

I saw that same statement, but I don’t remember where it was. White wheat is larger than red wheat in general, which I believe is what they are referring to. It’s still considerably smaller than barley malt. I’ve purchased white wheat from NB, Midwest, Morebeer and a LHBS. They were all the same size. I always crush wheat malt separately.

You can always a feeler gauge to identify the factory setting and reset it after you’ve crushed the wheat/rye. If you don’t have a feeler gauge, you can get one at an auto-parts store.