Benefits of Wet Milling and Grain Conditioning

Rumored to be originally popularized by traditional German breweries for more efficient lautering, grain conditioning is a simple technique that involves applying a small amount of water to a grain bill prior to milling. Over a small amount of time, this freshly applied moisture is absorbed into the husk of the grains which increases its pliability and resilience through the crushing process. With just a few household items and common brew supplies, homebrewers can easily reproduce this traditional method to increase the likelihood of a more uniform crush, better flowing filter bed, reduced astringency, increased mash efficiency, and much more. Here’s how to do it!

The Process

1) Gather up the necessary tools and resources. (The process can be replicated using a variety of different methods and gear, but I’ve found the tools listed below to work the best!) 


  • Scale 
  • Mash paddle or stirring stick
  • Spray bottle with mist nozzle
  • Grain and Mill 
  • Clean water
  • Large plastic bag or bucket 

2) After you’ve scrounged up your equipment and ingredients, you’re almost ready to get down to business. To calculate the amount of water you’ll need, take your overall grain weight and multiply it by 2%. Moisture less than 2% will likely have little conditioning effect on the grain, and much more than 2% just becomes messy and unnecessary. Here’s a calculation example for reference: (Grain Bill weight) X .02 = (H20 weight for conditioning) 11.25lbs X .02 = .225lbs conditioning H2O Or for more accuracy… 5103g X .02 = 102g conditioning H2O 

3) Now that we know how much moisture to apply for conditioning, we can fill up our spray bottle with clean water. Rather than worry about filling the spray bottle to the exact weight, I recommend filling the spray bottle completely up then taring or zeroing it on your scale. This quick trick lets you easily monitor the amount of water you’re using by periodically setting it back onto your balance and checking your negative weight. 

4) After preparing your spray bottle and scale, pour your entire grain bill into a large bucket or plastic bag. A larger surface area makes it easier to apply and mix your moisture in more evenly, so try and pick a vessel or bag which gives you plenty of room. With the grain in your container, mist the top of the grain bed, then use your mash paddle or stir stick to agitate and mix the grain around. Periodically, set your spray bottle back onto your scale to monitor your water usage. Repeat misting, stirring, and weighing until you’ve hit your target weight, and the grain is consistently moistened. 

5) Congrats, the hard part is over. Once you’ve applied 2% moisture, allow the grain to sit for 10-15 minutes. This permits the moisture to permeate and reabsorb into the husk material. After the hold, the husks should exhibit an almost rubbery texture. Proceed to feed your newly conditioned grains into your choice of mill and crush like normal. Feel free to check your grain after a few seconds of milling to make sure the crush looks good. The grain should look very uniform, and there should be very little grain flour or dust produced. In some cases I’ve seen my conditioned grains take up almost twice the volume of normally crushed grains due to increased hull integrity!  This grain needs a bit more water to get rid of the dry spots. And that’s it, in five easy steps you’re able to not only reproduce a traditional technique perfected long ago, but also gain more control over your brewing process! Time to kick back, relax, and have a homebrew (or get a batch of beer brewing!).

Quick Troubleshooting

If you’re still producing a lot of grain dust and flour material during milling, feel free to apply a little more moisture and repeat the conditioning process again. Alternatively, if your mill seems to be gumming up, you can pour your grains back into your conditioning container and allow them to dry out another 15 minutes, wipe out your rollers, and crush a small of dry grain through to clean it up again. Give grain conditioning a try with our all-grain recipe kits on your next brew day, and let us know how it goes!

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