Crushing It: Guide to Grain Crushing Methods for Homebrewers

by Brewing beer, Homebrewing

As homebrewers, we know the importance of good ingredients and proper equipment for creating our sweet sweet beer. However, one critical aspect that often gets overlooked is the quality of your grain crush. The grain crush refers to the process of breaking down brewing grains into smaller pieces that can be more easily extracted and converted into fermentable sugars during the brewing process. Let’s check out the importance of a good grain crush for home brewers and factors that impact grain crush, its effects on the brewing process, determining the right grain crush for our recipes, different grain crushing methods, and maintaining and adjusting grain crush.

Factors that impact the grain crush

When we’re crushing grains for brewing beer, there are a few things to keep in mind that can affect how our beer turns out. For one thing, the size of the crush can make a big difference. If the crush is too fine, we can end up with issues during the mash that can lead to off-flavors or a cloudy beer. It’s like brewing with flour. On the other hand, if the crush is too coarse, we might not extract enough sugars from the grains, which can result in a weak or thin-tasting beer.

Another thing that can impact the crush is the equipment we’re using. Some mills can produce a more consistent crush than others, and the condition of the mill rollers can also affect the final result. Some cheaper mills will pulverize the grain husks which can add tannins to the beer.

Tannins are a natural substance found in the grain husks, and if we crush the grain too fine, these tannins can be extracted from the husks and end up in the beer.  That gives the beer a mouth-puckering flavor like a tea bag. Tannins are a bitter, astringent compound that can give beer an unpleasant flavor and mouthfeel. They can also make the beer appear hazy or cloudy. While some tannins are necessary for adding complexity to the flavor profile of certain beer styles, too much can overpower the other flavors and ruin the beer.

To avoid extracting too many tannins from the grains, homebrewers should aim for a consistent grain crush size that is not too fine. This can be achieved by adjusting the settings on the grain mill or using a different type of mill altogether. Additionally, brewers should avoid over-sparging the grains, which can also lead to tannin extraction.  Ideally the grain mill should just tear the husk away without pulverizing it. An intact grain husk also helps with the sparge, much in the same way adding rice hulls improves the sparge.

Different types of grains can also require different crush sizes. Some grains are softer than others, so they might need a finer crush to extract all the good stuff. Other grains, like wheat and rye, can be tricky to work with because they tend to get stuck in the mash. These grains are softer, and can gelatinize leading to a stuck sparge. That’s where rice hulls  and intact grain husks come in handy! Adding rice hulls can help prevent stuck sparges and allow for a finer crush.

The brewing method we’re using can also affect the ideal crush size. For example, if we’re doing all-grain brewing, we’ll probably want a finer crush to get the most out of our grains. But if we’re using extract, we might not need to worry as much about the crush size.

Last but not least, the beer style we’re going for can play a role in determining the ideal crush size. Different styles of beer have different characteristics, so we might need to adjust our crush size accordingly. Wheat beers, for example, usually benefit from a finer crush, while lagers and pilsners might do better with a coarser crush for a nice, clear finish.

The effects of grain crush on the brewing process

When we’re crushing grains for brewing beer, we need to pay attention to the size of the crush because it can have a big impact on our final product. If we crush the grains too finely, we run the risk of a stuck mash. That’s when the grains form a solid mass that’s hard to move liquid through, and it can really slow down the brewing process. It sucks, and makes for a lousy brew day. Additionally, a too-fine crush can lead to tannin extraction from the husks, which can make the beer taste bitter and astringent.

On the other hand, if we crush the grains too coarsely, we run the risk of poor conversion. That means we won’t extract enough sugar from the grains, which can lead to a lower alcohol content and a thin, watery flavor. This is definitely not what we want! It’s important for us to find the sweet spot for our grain crush size to ensure that we get a good conversion rate and a flavorful beer.

One key factor to getting a good crush is consistency. If we’re using a mill to crush our grains, we want to make sure that the rollers are set to the same distance from each other every time. A consistent crush size ensures that we get an even extraction of fermentable sugars, which is critical for brewing a high-quality beer. Inconsistencies in the crush size can lead to variations in the amount of sugar we extract from the grains, resulting in an inconsistent final product. This alone is a good reason to get your own grain mill. Your LHBS usually has one setting, while you have much more freedom to adjust your mill to each grain for a consistent crush. The LHBS might let us muck with the settings, but they usually opt for a one size fits all solution. On the other hand, I’m sure they’d love to sell you a grain mill. They vary in price from $50 (USD) to several hundred dollars.

Determining the right grain crush for our recipe

When it comes to figuring out the right grain crush for our recipe, there are a few things we should think about. First, we need to consider the equipment we have, the brewing method we want to use, and the beer style we want to make.

To start off, we can look at the manual for our equipment to see what the manufacturer recommends for the ideal grain crush size. It’s not a bad starting point, but to make it more exact, we should look at a sieve approach for determining milling size. The basic idea is we mill a cup of measured grain in grams, probably 100g to have a nice round number to work with. Then we’d add the milled grain to a set of stacked sieves. We shake the sieves allowing the milled grain to separate into different sizes, and weigh the grain that separated into each pan. You’ll want to shoot for the normal values for most cases.

  #14 sieve #30 sieve #60 sieve Pan
Coarse 70-85% 70-85% 10-20% < 10% < 5%
Normal 50-60% 25-32% 7-11% 5-10%
Fine 15-30% 15-30% 25-40% 10-25%

(via How and Why Brewers Should Do a Sieve Analysis)

Depending on the brewing method we plan to use, we may need to adjust the crush size accordingly. For instance, if we are doing a BIAB (brew-in-a-bag) method, we might need a finer crush size than someone using a traditional mash tun.

The type of grains we are using can also affect the ideal crush size. Some grains are harder or softer than others, and this may require adjustments to the crush size to make sure we are getting optimal extraction. It’s worth noting that some grains, like wheat or oats, may require a finer crush to release their starches.

After taking all these factors into account, we should experiment with different grain crush sizes to see what works best for our setup. A Grainfather might produce different results than a more traditional brewing setup. This may involve some trial and error, but it’s worth the effort to find the right balance that produces the best results for our recipe.

Grain crushing methods

When it comes to crushing grains, there are a few methods we can use. One of the most basic methods is using a hand-cranked grain mill. This method allows us to crush grains manually, which can be a great option if we have a smaller brewing setup. Some of the benefits of using a hand-cranked mill include greater control over the crush size, and the ability to crush grains without needing electricity. However, it can also be a time-consuming process, and it may not be practical for larger batches.

Another option is to use a motorized grain mill. This method can be more efficient and faster than a hand-cranked mill, especially when crushing large batches of grains. The downside is that motorized mills can be more expensive and may require more maintenance than hand-cranked mills. Additionally, some models may not offer the same level of control over the crush size as a hand-cranked mill.

Finally, we can also choose to purchase pre-crushed grains from a reputable supplier. This can be a convenient option, especially for those who are just starting out and may not have the equipment or experience to crush grains themselves. Pre-crushed grains can be a reliable and consistent option, but they may not offer the same level of flexibility as crushing our own grains. Additionally, pre-crushed grains may not be as fresh as crushing our own grains, which could potentially affect the overall quality of our beer.

Ultimately, the method we choose for crushing grains will depend on our personal preferences, equipment, and brewing setup. Whether we opt for a hand-cranked mill, a motorized mill, or pre-crushed grains, the most important thing is to ensure a consistent and appropriate crush size to maximize our efficiency and produce the best possible beer.

Maintaining and adjusting grain crush

Maintaining and adjusting grain crush is an important aspect of homebrewing. To get the most out of our grains, it’s crucial to store them properly. Grains should be kept in a cool, dry place to prevent moisture from accumulating and causing mold or other issues. It’s also important to keep them in airtight containers to prevent pests from getting in. I use Vittles Vaults which work great in my dry climate. They are a bit expensive, but if you watch the prices on Amazon, you can often get them on sale for about $30 (USD).

Remember that the ideal crush size will depend on the type of grain being used, the brewing method, and the desired beer style. It may take some experimentation to find the perfect balance for your setup. But with proper storage and handling of grains, and the ability to adjust the crush size, you’ll be well on your way to brewing great beer.

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DJ Spiess

DJ Spiess

Beer buddy

I live in Denver, Colorado. This blog is everything about beer, wine, cider, mead and other spirits. I am a avid homebrewer and winemaker. I’ve been making my own beer and wine for many years. I started making beer when I was in college (mostly because the drinking age in the United States is 21). My first few beers were horrible. The beers are much better now, and I often supply my neighborhood with free beer! It is a great hobby! If you’re into computer programming, you might want to check out my programming site,