How do you compensate for lowered efficiency using wheat malt? Or is it even a problem for you? When I brew hefeweizens, I always see about a 5% drop in efficiency. It’s annoying. My mill gap is set at .035" and I double crush. This last batch it was a dunkelweizen with 52% wheat. I did a single infusion at 153 for 60 minutes and batch sparged. Preboil was 1.044 instead of 1.049. Argh. Ended up with 1.051 instead of 1.056, which is fine, but it’s still annoying.
Is there an actual reason why wheat malt is this way? Or is it because wheat is smaller and needs to be crushed finer?
It’s an issue with gelatinization of wheat. You always see that wheat gelatinizes at mash temperatures but that’s really for wheat starch. Whole grain wheat gelatinizes at temperatures closer to boiling (185-212). Crushed grain is going to fall in between and the more finely crushed your wheat the closer to starch temperatures you will get. However, without hitting a full flour composition you’ll never get the same type of gelatinization in wheat that you get from crushed barley. At mash temperatures for typical mash duration you are lucky to get 50% gelatinization, which means you’re only getting conversion on whatever is gelatinized plus the surface of non-gelatinized starches.
There is also research that suggests protein, for which red wheat is high, interferes with amylase and is likely further diminishing the efficiency of your mash. I suspect this is not a problem when using wheat malt, which is high in amylase, but is likely a problem in unmalted wheat.
Best way to get good efficiency out of wheat is to perform a cereal mash.
I agree with Keith (major) that it’s a size thing. Crush harder and you’ll have no problem at all with efficiency. Might become a stuck sparge thing after a certain point. So finding the right crush for your system can be a bit of a balancing act. Get your own mill (don’t trust the LHBS!), play with mill settings, and you’ll get there eventually.
This makes a lot of sense and explains the lack of conversion from raw wheat in the mash. It’s as if no wheat was added at all. I usually do a cereal mash instead of mashing the wheat in with the malt.
Thanks for the replies. I’ve wondered if it had to do with the wheat itself. It’s Best Malz weizen malz.
What does a cereal mash involve for this process?
Sounds like I could just plan to do a decoction with wheat beers or just plan for 5% lower efficiency. But Reverse’s description is a good one, kind of what I was looking for as to the reasons why wheat malt is a pain in the a$$ for hitting specific gravities…
I’m sure I could also crush finer too as .035" gap might not be small enough of a gap to crush it fine enough. It’s a pain to mess with that though with a Barley Crusher…
I can not understand what a cereal mash would have to do with wehat malt, he must be thinking raw wheat. I do agree that wheat does seem to be harder than barley so gelatinization could be part of the issue, a decoction will definitely increase your efficiency regardless of wheat or barley IME. You also might just try a little longer mash or add 5% more ingredients.
Mosher said somewhere, read on a blog, that using a commercial coffee bur grinder works well for wheat. There isn’t a husk, so no point being gentle. I’ve been wanting to try a food processor, but haven’t found the motivation to run 4-6lbs through 8oz at a time.
I think it must be a gelatinization issue, which is fine. I’m just frustrated I can’t get the same efficiency, but using 5% more isn’t a big deal and I may try decocting on my next hefe. Maybe even a single decoction will be good enough.
Steve, I’m not sure I’d want to run wheat through my food processor. I’d think it’d seriously dull the blades…
Malt or no malt, doesn’t matter. The gelatinization range doesn’t change with malting.
You don’t need to do a cereal mash; all you really need is to boil the wheat so it gels. However, it might make sense to go ahead and try to get whatever conversion you can out of the wheat before boiling and denaturing all those enzymes. It isn’t necessary to add barley, since the wheat malt has enzymes, so perhaps cereal mash is the wrong term but the correct process.
For most breweries it’s not an efficient use of time or resources to boil wheat to try to make up for a 5% efficiency drop. It’s just easier to accept lower efficiency or mill as tightly as possible to create more surface area and hope for the best.
I was having trouble finding the reference. I know he said his AHA Q&A that he did this for raw wheat. Maybe where I read it had it wrong. I still suspect that that pulverizing wheat malt to dust can’t be very harmful beyond a slow sparge.
I did this once. Ran 6 lbs. through my VitaMix blender dry container until it was flour. Added 4 lbs. of normal crushed 2-row, and rice hulls. I got great efficiency, and the beer came out great.
It only took like an extra 10 minutes to crush this way.
Part of the reason to do a mash with some barley malt before boiling is so the cereal mash doesn’t turn into a gloppy mixture that will stick your mash.
I feel we’re being ignored. Here, let me be more clear:
There’s no need to dick around with mill gap settings. If you don’t crush the wheat properly, your efficiency will suffer. If you don’t crush the wheat properly, you aren’t crushing anything hard enough. Set the mill gap tighter, and crush everything tighter. That includes barley malt, wheat malt, rye malt, oat malt, corn malt (where can I buy some of that!?), you name it. Set the gap tighter, crush everything harder, and be done with it.
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