How to Crush Your Own Malts
Homebrewing is labor of love. And whether brewing an all-grain brew, or adding specialty grain to an extract based wort, crushing malts is part of the process.
However, when starting out homebrewing, it can be all too easy to overlook the importance of milling grains.
In this post, we’ll look at how to crush your own malts, so that you can get the most of your grains when brewing, avoid stuck sparges and ensure that your brew yields all the delicious bounty you hope for.
Why You Crush the Malts
When all-grain brewing, proper milling is important because it ensures that the starches, sugars and enzymes present in the grain will be exposed to water during mashing. This activates enzymes and converts starches into sugars for later fermentation.
Specialty grains such as roasted barley, crystal malt and chocolate malt, to name a few, are typically used to contribute flavor and color to the wort. In theses cases, the way you crush the malts is a little more forgiving since they are not being used as fermentables.
Crushing Malt the Right Way
Now that you’ve got a basic understanding of the purpose of crushing malts, let’s talk about the objective. Ideally, when milling grains, you want the husk come away from the kernel and remain as intact as possible, while the endosperm is broken into small pieces.
Getting the right crush is somewhat of a balancing act. The more intact the grain, the easier water will flow through. But the grist is less exposed, meaning less conversion of starches to sugars and activation of enzymes. In other words, less yield.
A finer grist will mean more yield from the grain but there will be less flow, which means higher chances of a stuck sparge.
Keeping husks mostly intact, will allow adequate filtering in the grain bed, creating small spaces in the grist, allowing water to flow through. Charlie Papazian, in his book The Homebrewer’s Companion, recommends aiming for an equal mix of grits (the small bits) and rough to fine flour.
For obvious reasons, one should avoid pulverizing the grain into flour which is why using food processors or coffee grinders is problematic. Think about how flour gets when mixed with water: it turns into a thick, glue-like paste. Water can’t flow through a globs of gelatinous goo.
Methods for Crushing Malts
So, what is the best way to crush your malts? There are many approaches. When using specialty malts, you can often get by with something as low tech and inexpensive as a rolling pin.
Specialty grains are usually steeped in the kettle with the wort and do not contribute significant fermentables. How they are milled is not as critical as when the grains will be mashed. Conversion of starches to sugars is less of an issue, therefore it’s less important how much the grist is exposed to liquid.
If using a rolling pin, put the grain in ziploc bag and roll it until suitably crushed. Using a marble rolling pin is helpful since grains are pretty hard and may put dents in a wooden rolling pin.
Types of Mills
When it comes to crushing your malts for use in all grain brewing, you’ll want to consider an upgrade from the rolling pin. Also, coffee grinders and food processors aren’t great options since they pulverize the husk and grain too easily.
Your best bet is using a mill. The two major types useful for homebrewing are flour or grain mills and roller mills. Flour mills work by crushing the grain between two plates that rotate against one another.
Although, plenty of homebrewers use flour mills with success, the downside can be that the husks break down into small particles along with the rest of the grain. Smaller husk particles mean less flow through the grain bed and more potential for stuck sparges. However, one way to compensate for this is to simply spend a few dollars extra on a bit more grain.
Roller mills are arguably the best way to go when it comes to crushing malts. With roller mills, the grain passes through two to three cylinders. The husk is crushed and torn away while the endosperm is broken into bits by the rollers. The space between the rollers can adjusted based on the grain size of the particular malt you’re using.
The advantage of a roller mill over a flour mill, is that if set properly, it will keep the husks mostly intact while crushing the endosperm into a good balance of grits and flour of various texture.
Of course, some roller mills do a better job than others. And even small roller mills can be an investment. If you don’t want to shell for a roller mill, many homebrew shops have mills you can use. Or they will often do it for you.
Safety Tips for Milling
Many mills (especially the most affordable ones) have a hand crank. When crushing more than a couple pounds of grain, this can get tiring rather fast. There are ways to motorize your mill however. A popular option is to rig up a drill to the shaft of the mill.
Some things to consider when using a drill are the power and torque of the drill. Use a drill that has enough power to withstand turning the mill for a reasonable length of time without overheating.
The other thing to keep in mind is safety. Using a powerful drill with a lot of torque can be hazard if a stone gets lodged in the mill rollers and shears off the shaft. Watch your fingers and clothing as well, and don’t leave the drill unattended while it’s running.
Be aware that dust is combustible and becomes a fire hazard if it is concentrated in an enclosed area.
You may not be milling enough that you’re kicking up a ton of dust, but err on the side of safety. Be sure to have good ventilation. All it takes is a spark!
Also, be aware that grain dust carries bacteria which can spoil your brew, so mill grains away from your fermenter.
Additionally, it can be helpful to have a second person to feed the grain in while running the drill.
And finally, always use care when operating electrical tools around water or moisture. Don’t get electrocuted!
In the end, while crushing malts is important to the outcome of your homebrew, it doesn’t need to be difficult. I hope this post gave you a good understanding of the process. With the proper tools and the knowledge of how to balance yield and flow, you’ll master milling in no time.
Craft The Best Beer You'll Ever Taste
Advice for modern brewers seeking to craft the perfect pint. Subscribe to our weekly homebrewing newsletter.