North Houston's source in Humble, TX for Homebrew Supplies
North Houston's source in Humble, TX for Homebrew Supplies

Grain Crush and how it affects homebrew

What is Grain Crush?

What is it with grain crush and how does it affect your beer?  When it comes to homebrewing efficiency in all grain brewing, properly crushed grain ensures that you get maximum extraction from the grain and the hull creates a good filter for the water to pass through.

No Grain Crush

Homebrew Efficiency

I have noticed efficiencies as high as eighty five percent when the grain crush is correct.  Most homebrewing software sets homebrewing efficiency to seventy two percent. This is an average and can be changed to reflect your own efficiency. Good grain crush also has the effect of slowing down your sparge, but that’s not a bad thing and I will talk about that in a blog later.  So what is grain crush? Grain crush is where the hull and kernel are separated leaving the hull mostly intact and the kernel broken and ejected from the hull.  This ensures that you get maximum extraction from the grain and the hull creates a good filter for the water to pass through.  If you use the “Brew in a bag” or BIAB method, you will want a much finer crush than what normal brewers use.  So you should normally mill twice to account for the smaller size requirement.  I have also read that a better crush on the grain equates to beer that has more body and flavor. But that is only what I have read and I have not performed experiments to verify this (See Brulosophy’s 2015 article “Mind the gap”).

Grain Size of Rye, 6 Row, & 2 RowKernel Size

You should note that the grain kernel size changes and that not all grains are the same size.  There are significant size difference between rye, six row, and two row.  Most, if not all homebrew stores are not in the habit of changing the gap size to accommodate the differences in kernel size.  So if you are adding these to your recipe, I highly suggest to mill them separately and make sure you run it through the mill twice to ensure that the grain is properly milled…


Typical mill type

Most Houston homebrew stores have a modified homebrew mill (2 or 3 roller) with an enlarged hopper and some sort of catch system with a bucket under to catch the grain.  These types of mills are usually not meant for the type of abuse that a normal homebrew store can dish out.  The constant daily usage and dust buildup can wear the moving parts fairly quickly which can make the grain crush change.  The alternative is for you to purchase your own grain mill, where you can ensure that the grain is milled to your satisfaction.  However if you are unable to make that purchase and are relegated to using the mill at the local homebrew store.  Here is what you do, add a small amount of grain to the mill and inspect the grain crush.  If it is not to your liking, run the grain through the mill a twice to ensure you have a good crush on your grain. Or if the store employee is running the mill, ask them to run it through twice. They usually don’t mind and usually know exactly why you are asking…

The Grain Cellar’s mill

If you are homebrewing in Houston and would like the use of a professional mill that is serviced on a regular basis.  One can be found at The Grain Cellar in Humble!  Or if you would like more information please leave me a comment below, and I will help in any way I can.  You can also stop by for a homebrew and speak with me directly!



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