How to mill your malt
As a brewer you should already know that grains must be crushed to have access to the starch and produce fermentable sugars during the mash. Crushing malt for your homebrew will make your life easier, since you don’t have to visit your homebrew shop each time. As you can buy the malt in bulk and don’t have to pay for the milling, it also saves you money. Besides, it gives you more control over your recipes. All in all, properly crushed malt is one of the most important steps to brew the perfect beer.
Ideal crush opens the husk and pulverizes the inside of the kernel. The more you can get access to the starch grits, the higher yield you have. The husks act as a filter in your mash when your beer wort flows through the “grain cake” during lautering and sparge. What if you brew with flakes or wheat? Just add a few handfuls of rice hulls to replace the missing husks. Flakes being mentioned, you don’t need to let them through the mill.
What kind of equipment to choose? For general homebrew volumes a two-roller mill should work well. You only need to adjust the gap to find the right level of crushing. Should it be too tight, your grist will be floury, could cause stuck sparge and result in a hazier beer. In case it’s too loose, kernels would not break optimally, thus your extract yield will be lower. Best result is to have cracked husks and pulverized grist (see on the picture). Feel free to use a bankcard to set the right space between the rollers.
Before you crush the whole package, it’s wise to do a trial by running a handful of malt through the mill, so you can check if your grains are crushed optimally. You can do some exercise by manually crushing your malt, but an electronic drill could be a big help. Just start gently and make sure it is not set to the top speed then, otherwise milling would be more intense than required.
What else do you need? A scale to properly weight your grain bill, a bucket for the grist, a grain hopper, which usually comes together with your equipment. That’s all. The process may be very dusty, so you’d better do it outside. And make sure to clean all the equipment you used.
What if you grind your grains, but decide to use them later? How long do they last? The fresher the better – for the best results crush your grain right before you brew. Otherwise, milled grain can be stored for even a year in an air-tight bag with proper sealing, but you’d better use them within 2-3 months.
Let’s crush the malt!