The Rebel Grain Mill: One of my most coveted new pieces of equipment

I have not blogged extensively about my recent attempts at all-grain brewing, for several reasons: no time, not sure how to formulate my thoughts, but mostly I’ve just not been able to work up the heart to put effort into what will ultimately be an exercise in frustration. You see, I have hit an extraction efficiency of approximately 52% in my brewhouse. That’s pretty abysmal to my way of thinking. I don’t expect to hit 100% in my cooler-turned-mash-tun, but I certainly expected to be well north of 52%. All of that has conspired to create beers that are thin-bodied, with a low-malt flavor profile. I’m hoping with some new equipment and processes all that will change, and here’s why.

When you make beer, the barley you use is not simply plucked from the stalks, thrown in a bin and proclaimed ready for prime time.  There’s a lot that goes into the making of malted barley before it even gets to the homebrewer. Once it gets to the homebrewers, however, what we do with this is a crucial aspect of the beermaking process. See, the barley all encased in its husk is inaccessible to the brewer. The brewer cannot get at that starch to convert it to fermentable sugars. And without fermentable sugars, you don’t have beer…not much of one, anyway. The efficiency of a brewhouse in obtaining the most sugars possible from their grain is always something brewers work to improve. So this is one area I was having problems: extraction efficiency.

In any grain, there is a maximum possible amount of sugars. We call this dream-number 100%. No one hits 100%, but it’s a number we all shoot for. In a perfect world, brewers would extract 100% of the sugars from their grain while not extracting any tannins from the husk. That’s the balancing act. The closer you get to 100%, the more likely you are to extracting harsh tannins, and the hotter water you use, the same danger is present. Homebrewers, then, have to be satisfied with lower numbers to make great tasting beer. We frequently do not have the access to equipment that allows for fine-tuned adjustments to temperature, etc. 70% to 75% is average, but 80% or more is not unheard of in homebrewing circles. However, the 52% I am estimating I get in my brewhouse, is not satisfactory. With that number, I am having to buy something like 33% more grain just to make up the difference. I also feel like I am wasting barley. So what can I do to improve things? Well, one aspect that has a tremendous amount of anecdotal evidence to support it is that the crush a homebrewer uses has a lot to do with their extraction efficiency.

Brewers use crushed barley to make their beer. They either pay to have someone else crush it, or they crush it themselves. Crushing barley requires a device used to crush grains, but with a crucial difference from regular grain-crushers: Namely, you don’t want to crush it to fine flour, husks and all. That would theoretically garner the highest efficiency, but would contribute a large amount of tannins, and would be exceedingly difficult to drain or lauter all the liquid out to get your wort. You’d have a gooey mess on your hands/ Crushing barley requires exposing the starches while leaving the husk of the barley essentially intact. The husk, then, acts as a filter to hold back the stuff you don’t want in your beer. A good crush helps pulverize the starchy insides, while leaving the husks mostly intact to provide a good filterbed. It’s a balancing act as well. This is where specialized grain crushers come in, and this is where my new Rebel Grain Crusher makes its appearance.

image The Rebel Grain Mill: Designed by homebrewers for homebrewers. The hopper and most parts are made of stainless steel. The side plates are aircraft grade aluminum, and the bushings look to be bronze. The rollers are tool steel, and it’s designed to be powered by a drill. This thing chews through 7.5 lbs of barley in less than a minute! It comes preset to the best width between the rollers from the factory for the best crush, resulting in the best efficiency. I can’t prove that the crush from my local homebrew store (whom I love, by the way) was poor, but I know I used to get better efficiency when I bought my grain online. When I brought my problems up to the homebrew forums on which I participate, they immediately looked to the crush, which frustrated me.

So I went to and bought this behemoth of a crusher. Tomorrow is the real test, and I am really, really looking forward to it. My hopes are that I realize the same increase in percentage of efficiency that others have reported: 10%. That, when coupled with the other changes in my process which I am making, should put me into the 75%+ range that I hope to be in. (I’d be happy with even more.)

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