Milling grains play a key role in the development and production of beer, and this is an important step in brewing because it breaks down complex carbohydrates into simple sugars that yeast can use to produce alcohol.
The process also helps brewers control the amount of residual sugar left behind after fermentation.
We took a closer look at the milling grains that are used for beer, and how they affect the flavor of your brews – read on for all you need to know!
What Are Milling Grains?
In the simplest terms, milling grains is a term used to describe the process of turning grains into flour ready for them to be used in food, beer, or other uses.
A milling grain, therefore, is any cereal grain that is used to make flour. Flour is made by grinding grains into a powder.
There are two main methods of milling grains: wet milling sees the grain steeped in water and cooked before being ground, while dry milling sees the grain go straight from being soaked to being ground.
There is no cooking involved. Instead, the grain is treated like coffee beans. Chemicals are added that help separates the brain from the germ. This process is faster than wet milling, but not quite as efficient.
It takes less energy to cook the grain than it does to grind it. That means you’ll need to use more fuel to make beer.
In short, milling grains is a process that involves soaking the grain, steaming it, drying it, and finally crushing it. Each stage requires different equipment, so each type of grain needs its own dedicated set of tools.
1. Soaking
Soaking is the first step in the milling process. The goal of this step is to soften the outer hull of the grain. When the grain is softened, it becomes much easier to remove the bran and germ.
Soaked grains are placed in large tanks called lauter tuns. Lautering is the German word for “to wash.”
During lautering, water is pumped through the grain at high pressure, and this practice loosens the bran and germ, allowing them to fall to the bottom of the tank.
2. Steaming
Steaming is the second step in the milling procedure, and this helps loosen the bran and germ even further. Once again, this makes the grain easier to separate later on.
Steamed grains are transferred to large stainless steel vessels called decoctions. Decoction kettles are typically cylindrical with flat bottoms and are designed to hold about 10-15 gallons of liquid at one time.
3. Drying
After steaming, the grain is dried. This is done by spreading the grain out on concrete floors or racks – concrete floors are best because they allow air to circulate underneath the grain, and this helps to prevent mold growth.
Dried grains are moved to another room, where they are spread out on wooden tables to dry.
These rooms are known as kilns. Because wood absorbs moisture, these rooms are kept relatively humid.
4. Crushing
Once the grain is completely dry, it’s time to crush it. Crushing removes the husk (the outer layer) of the grain.
The husks can contain nutrients such as iron and zinc, but they also act as an insulator, preventing heat from escaping during fermentation, and this is why they are removed.
Crushed grains are transferred to storage bins. Storage bins keep the crushed grains separated until they’re ready to be sold.
How Are Milling Grains Used?
Despite this being the most well-known use, milling grains aren’t just useful for making beer. Brewers use them to make other products like malt extract, whiskey, vodka, and more.
Malt Extract
Malt extract is made by extracting sugars from malted barley. Malt extract is then boiled down to create a syrup. The syrup is stored in barrels and eventually bottled.
Whiskey
Whiskey is distilled from fermented mash, this is a mixture of mashed potatoes and malted barley. After distillation, the resulting spirit is aged in oak barrels.
Vodka
Vodka is distilled from the fermented mash, but instead of being aged in oak barrels, it’s often filtered through charcoal filters.
Beer
Most brewers use some form of wheat when brewing their beers. Wheat is commonly milled into flour before it’s added to the grist.
Flour
Flour is used to add body and texture to bread, pastries, and pizza crusts. It’s also used to thicken sauces and gravies.
What Are Milling Grains For Beer?
Milling grains are the raw materials that go into making beer. They include malted barley, wheat, oats, rye, corn, rice, buckwheat, millet, sorghum, spelt, triticale, and other ingredients.
These grains are milled or ground up so that their starches and proteins can be converted into fermentable sugars by enzymes called alpha-amylases. This is what makes them suitable for brewing.
Milling grains is a crucial part of the brewing process. It’s the first step in converting starch into sugars that yeast can then convert into alcohol.
In addition, mashing allows brewers to control the level of residual sugar remaining in the finished product.
The most common types of milled grains used in beer are as follows:
1. Malted Barley
Barley is one of the oldest crops known to man. It has been cultivated since prehistoric times and was originally grown primarily for its nutritious grain. Today, barley remains one of the world’s primary sources of food energy.
Malting is the process of germinating barley seeds before they’re harvested. During this time, the plant undergoes several changes, including the conversion of starches into sugars.
When the barley kernels are ready to harvest, they are dried, cracked, and steeped in water. After soaking, the malt is separated from the husk and the rest of the kernel.
After being dried, the malt is crushed and mixed with hot water. The mixture is allowed to sit for about 30 minutes, during which time enzymes break down the starches into sugars. The resulting liquid is referred to as wort.
Wort is then boiled until it reaches a specific gravity (SG) of 1.050. At this point, the wort is cooled and transferred to a vessel where it will be fermented by yeast.
Brewers often add hops to the wort to impart bitterness, aroma, and color. Hops contain compounds that inhibit the growth of unwanted bacteria and fungi.
Brewers may also add adjuncts such as rice, corn, oatmeal, molasses, honey, and other ingredients to increase the body and mouthfeel of their beers.
2. Wheat
Wheat is another ancient crop that dates back thousands of years and is a hardy grass that grows well in many different climates around the globe.
It is perhaps less well known as a milling grain, but nonetheless plays an important role in the brewing industry.
Like barley, wheat is typically soaked and steamed before crushing. However, unlike barley, wheat is not usually mashed. Instead, it is added directly to the boil.
3. Oats
Oats have been cultivated for more than 5,000 years. They were domesticated in Europe sometime between 7,500 BC and 4,500 BC. Oats are among the earliest cereals to be cultivated.
Like barley and wheat, oats are traditionally steamed and then crushed before being added to the mash tun. Using oats as a milling grain for beer offers some unique advantages over using barley.
First, oats are much easier to grind than barley. Second, they produce a smoother texture when brewed. Finally, because oats don’t require a long soak in the same way that barley does, they can be processed faster.
4. Rye
Rye is native to Russia and Eastern Europe and has been cultivated there for at least 2,000 years. It is now widely planted throughout the Northern Hemisphere.
Rye is similar to barley in that it must first be soaked and steamed before being crushed.
Unlike barley, however, rye doesn’t need to be mashed. In fact, it’s rarely mashed at all. Instead, brewers simply add rye to the boil kettle.
This allows the starch in the grain to convert into sugar without having to go through the lengthy step of mashing.
5. Spelt
Spelt is a relative newcomer on the scene. It was developed in Germany in the late 1800s and is thought to have originated somewhere in Turkey or Greece.
The most common spelt used today comes from Hungary. It is very similar to traditional bread flour, except that it contains slightly higher amounts of protein and minerals.
This is a milling grain that should be considered if you want to make your own bread.
Final Thoughts
The best milling grains for beer are those that will contribute the most flavor and aroma to your finished product.
The options that we have discussed here are just some of the many varieties available but are usually the most popular and widely used.
