Does rye/wheat affect mash efficiency?

My last 3 beers have been rye/wheat (about 50%) based and I have been getting lower mash efficiency. I haven’t changed anything in my system and even did a protein rest at 122F. Anyone have any issues with these grains?

This was just discussed on another forum.  The conclusion was that wheat and rye are smaller in size and physically harder to crush than barley malt, so it’s likely that they weren’t crushed enough.  Could that be the problem for you?

It’s funny that you mention that. We actually talked to our homebrew store guys about what we thought were uncrushed grain in these beers. They said that they keep the mill updated to their normal crush size and we’ve made over 35 beers with them. We knew that they don’t have husks and are smaller but for some reason didn’t realize that. So I guess the answer is to crush them separately, get them home and crush them again yourself (light blows with a blunt object in our case)? That makes sense. Sorry for the redundancy.

As you are not really concerned with husk integretiy you could pop them in the food processor or blender to. A little quicker than the blunt object route. Just don’t make flour

Thanks guys, solves that problem.

I agree it’s most likely the crush but FWIW I just run everything thru my BC and my efficiency is nominal with Rye/Wheat.

But just last weekend I made a Roggenbier with just under 60% Rye and my mash pH was noticably higher than I expected (and higher than Bru’n water predicted by a good amount).  I remember reading on another forum that Rye/Wheat often have this effect on mash pH and could affect efficiency.  Might not be the problem but mentioning it just in case.

EDIT: I just added some lactic acid to bring it down and efficiency was nominal.

Same here.  I assume that it’s because I have the gap on my mill set so far down.

Ditto – I’ve had zero problems with efficiency with wheat or rye.  Set your mill good and tight and it’s a non-issue.