Okay, I'll be the first to admit I don't do this very often. But I stand by my subtitle. It is fun. And it's totally worth the hassle. There's something rewarding about seeing the entire process, from raw agricultural produce to finished beer, that you just don't get with purchased malt.

There's a reason I don't do it very much though. It's time consuming. You need special equipment to get consistent results. Perhaps above all, you need a consistent supply of raw barley or other grain, and the quality and variety matters a lot.

Even commercial breweries, almost all of them, in fact, buy malt from maltsters rather than produce it themselves.

If you do want to try it, and I'm adamant that every brewer should try it at least once, you'll find there's quite a lot to it. Perhaps as much as brewing the beer itself.

What follows is a general outline of the process, to help you decide whether you want to take a crack at DIY malting. If you're ready to actually try it out, I have a process you can try at home.

What is Malt, Anyway?

In short, malt is cereal grain (usually barley) that’s germinated just enough to activate enzymes and open up the endosperm, then dried to stop growth and set flavor.

You can malt barley, wheat, rye, or even oats, but barley is easiest and most forgiving, and it often forms the base of a given mash. It has the best husk for lautering, for example, because the kernels keep a tough, papery husk after malting. When you crush malt properly, with the endosperm cracked and the husk mostly intact, those husks interlock and form a porous grain bed that naturally filters the sweet wort. This reduces flour fines in the kettle and speeds runoff.

Barley also has high diastatic power, which is to say it brings a lot of starch-converting enzyme to the mash. It’s mainly α-amylase, β-amylase, and similar (limit dextrinase, β-glucanase, proteases). Units are often °Lintner (°L) in the United States. Essentially, you want enough enzymatic power to fully convert starch in the mash.

Can You Use Grains Besides Barley?

A lot of mashes contain a mixture of grains, and these grains need to be malted just like barely. Wheat malts well, but lacks the same husk that makes barley so good for lautering. With wheat, it's often a sticky affair. Rye also lacks the husk, and it's also high in beta-glucans, which can make the runoff gummy. Oats can be malted but their enzyme power is modest at best. More often, it's used unmalted or flaked for body or silkiness.

How Sprouted Does the Grain Have to Get?

Allow me to introduce some more lingo (I warned you there was at least as much to malting as there is to brewing): brewers watch the acrospire, the shoot under the husk, as a quick proxy for modification, the degree to which the kernel’s interior has been biochemically and physically opened up by germination.

Put it more simply: you look at how long the sprout gets.

There's a lot going on within the kernal during steeping and germination. The embryo secretes hormones that trigger the production of enzymes. We need those enzymes to help release the starch trapped in the grain, among other things.

As it happens, when the acrospire is about ¾–1x the length of the kernel, that usually means the enzymes are built, the cell walls and protein matrix are loosened, and the endosperm is mash-ready. It's not a perfect indicator though, and it should be paired with a few other quick checks.

Take the chew test, for example. When you chew them, the kernels should be mealy and easily crumbled, not glassy or steely. The taste should be lightly sweet. You can also inspect the rootlets, known as the chit. They should be abundant, white, not browning or slimy. These are indicators of good germination health. Lastly, you can feel and crust it. It should grind easily without turning to powder, and the husks should stay mostly intact.

Once you've sprouted the grain to a sufficent degree, which usually takes about 3–5 days at ~60 °F (15–18 °C) with regular turning, you can either use the green malt and mash it immediately, or you can dry it as is the more common practice.

Does it Have to be Dried?

Freshly malted grains spoil quickly, and even more importantly, you want to stop germination once the malt reaches the target modification. As I mentioned, you can just use the malt immediately. You should know, however, that green malt is wet, spoils fast, and is messy to grind.

For all other use-cases, you generally want to dry the malt to about 4–6% moisture. This stops growth, stabilizes the enzymes, and sets the malt's flavor.

We can split the process into three phases, starting at low temperatures to start. You really want to avoid what's been called case-hardening, a process by which sugars on the outermost layer of the grains start to crystalize and harden, which traps moisture and hurts enzyme activity and storage life.

Wither

The first phase is characterized by high airflow and relatively low heat. Painting broadly here, the malt might spend between 6–18 hours at 95–120 °F (35–50 °C) with continuous airflow. The grain should be turned regularly, at least hourly. At this stage you're trying to bring the moisture down to around 10%, where the kernels will start to feel leathery and more brittle, the rootlets start getting crisp, and the aroma begins shifting toward cereal.

Dry to Safe Storage

Secondly, you want to increase the temperature a bit and dry the malt to the point it's safe for storage, usually around 4–6% moisture. This might take another 6–12 hours for small batches with good airflow. There's a way to test this with no equipment: you weigh a sample of the malt, then you dry the sample to an extreme degree, so there's no moisture left at all, and weigh it again. The difference is the moisture content that was contained in the original sample.

Cure

Lastly, you'll continue using heat to cure the malt. This gets the Maillard reaction going to provide toasty notes, and it “sets” the aroma typical of malt. Without curing the malt would smell more like fresh grass (which is what it is, actually). For a pale or base malt, for example, you might cure between 175–185 °F (80–85 °C) for 1–3 hours. The longer and hotter you cure the more flavor grows, but at the cost of enzymatic power.

Finishing the Malt

Once you've cured the malt, you need to bring it down to room temperature before you can bag it up for storage. If you bag it warm, the malt will sweat and re-wet itself. You may also want to polish the malt to remove the rootlets and sprouts, which improves storage.

Generally, you want to let the finished malt rest for 24–72 hours in a breathable container. Moisture equalizes, the kernels become uniformly friable, and crush improves. Try chewing on a few of the kernels they should be mealy and snap cleanly.

Store it in a cool, dark, dry place, in a sealed food-grade bucket or mylar bag. Label it with the date and information about the drying profile.

Going Further

Sounds pretty involved just to end up at the very beginning of the beer-brewing process, no? This is the main reason I don't do it very often.

But what if you're working on historical recreations and you need a smoked malt? Or one with very low modification? What if you want to turn the grain you grow on your land into beer? What if you just want to understand what malt is, where it comes from, how it affects the later brewing processes?

All these scenarios could give you the motivation to become a maltster. You can start doing it at home, you don't need fancy equipment. On the other hand, if you're thinking about doing this on a commercial scale for whatever reason, maybe instead of brewing you do actually want to focus on malting, then you'll need proper equipment and larger volumes to achieve any kind of consistency.

But think about the upside: you'll unlock the 10–15% of flavor and control that only the maltster touches, the part most homebrewers never get to steer. Imagine tasting a pale ale whose gentle biscuit note isn’t an accident; it’s the direct result of your germination schedule and the way you dried that grain last Sunday. That’s true authorship at the deepest level of the craft.