Raw Grains: How Best to...

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Jul 24, 2018
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I am mashing in a bag (@wilserbrewer), in a standard three vessel system. I like the efficiencies of a finer milling, hence the bag, and I batch sparge with a solid bag squeeze at the end. As many do, I have used/use flaked grains bought from either the the LHBS ($$) or the grocery store ($). They mash just fine and go through the mill or not, I don't notice a difference either way in efficiency or wort collection.

I have also used various grits, usually bought from the grocery store, cooked in a cereal mash in advance. These I just add to the mash with the rest of the grain when the strike water goes in.

Lately, I have been getting whole raw grains from a neighbor who bakes. So here's the details:

Experiment #1-Raw Rye, ground with the rest of grain, gave a great flavor, but I don't think it gave much up in the way of fermentable sugars.

Experiment #2-Cereal mashed Whole Rye, drained and mixed with the grain and then milled. FYI, don't do this. Ever. I spent a half hour more than normal unclogging the mill because the wet grain just stopped it. I thought I was going to burn out my drill (it smoked a bit). I normally do a double grind anyway, but this time I had to do it because I had to keep running the mill backwards to loosen the grain, ensuring that a lot of the grain passed through unmilled. The second pass, the wet grain flattened out to flaked size, which I thought was cool, but not cool enough to take an extra half hour and kill the drill. I almost hit my efficiency numbers on this batch.

I have a bag of already mashed (and frozen) whole grain rice that I plan to use in an upcoming lager. So here are the questions.

1. Should I just throw the cereal mashed grains straight in the mash tun, and hope the enzymes get into them and break them apart? Or should I find a way to smoosh them a bit first, rolling pin, something, I don't know.

2. In the future, how best to deal with raw, whole grains? Grind them and then cereal mash?

Any help is appreciated, folks!




Well-Known Member
May 10, 2011
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I think a straight toss in will get you the rye experience at best, a bump in flavor (if the husks have something to give in that department) and nada on fermentables. The water / enzymes will simply not have enough time / driving force to get in let alone convert.

I would suggest some breaking method in advance, and maybe some experiments with mill gap are in order to see if it can handle the tougher job. To avoid PITA rolling pin, an alternate might be your car, e.g. putting a single layer in a ziplock bag (or tougher bag as might be prone to tearing) sandwiched between two plywood boards and giving it the old heave ho. Since you don’t care if it’s overly crushed, might save your drill and mill from an untimely demise.


Supporting Member
HBT Supporter
Nov 26, 2010
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Experiment #1-Raw Rye, ground with the rest of grain, gave a great flavor, but I don't think it gave much up in the way of fermentable sugars.
Go back and check your recipe and do the math. I'll bet they converted just fine. Malted Barley has sufficient excess enzymes to convert itself plus almost double its weight in unmalted grains.