Beer is made from malt. With this article, we want to tell you more about barley malt: what it is, how it is used, and its effect on beer. After reading this article, you will know what amylase is, what the aleurone layer of a barley grain does, and why barley malt is the most commonly used type of malt.
First, let me explain what malt is; malt is malted grain. This means that after harvesting, the grain undergoes a process called malting. The grain is moistened, after which it remains in a warm and well-ventilated space for a certain period. The grain, which is a seed, begins to germinate! The moisture and warmth "wake up" the grain. It "thinks" it's spring and starts to grow.
During germination, the grain produces enzymes that can break down the starch of the grain into sugar. Enzymes are, as it were, tiny protein factories (remember this) that have one specific function. Amylase is released in the grain; this can cut long starch chains into pieces, releasing sugar.
The small plant uses the sugar to grow. For plants, sugar (just like for us) is fuel. However, the seed does not get much time to grow. It is precisely the enzymes that we want, not the plant. The temperature of the room is increased, and the grain is turned over with the aim of drying the malt. When the malt is dry, the seed can no longer germinate, and the process stops.
The most commonly used type of grain is barley. Such a seed consists of the germ, the endosperm (flour body), an aleurone layer, and a husk. The germ is the embryo of the plant; when the seed has germinated, it is the germ that begins to grow. The endosperm is made mainly of starch, a form of sugar made from long chains of glucose. When the plant starts to grow, it breaks down the starch chains so that it has the energy to grow. The aleurone layer is a protein layer; this is where the amylase comes from. This enzyme, amylase, is therefore essential in breaking down starch. The husk is a hard shield that protects the grain from external dangers.
Starch is actually a molecule that plants create to store energy. Starch molecules are too large for many organisms to eat. As a result, starch does not decay, and a plant can therefore store energy with it for when it needs it later. To access the energy contained in the starch, it must be broken down into smaller pieces. This allows small organisms to eat the starch. The breakdown is therefore done by enzymes.
These enzymes need moisture and warmth to work. That's why the dried seeds (the malt) are placed in warm water during the brewing day so that the enzymes can do their work. However, there is then a problem; when the enzymes have finished their work, we want to separate the sugar and water from the residual material of the malt (the germs, husks, and other residual products). This is where the barley husks come in! By pumping the mash past a filter, a larger filter can be made with the husks. Because sugar is soluble in water, all the sugar can be extracted from the mash.
Barley is not only the only grain with a husk suitable for making this filter; barley also has an enormous amount of those amylase enzymes! This ensures that the saccharification of the grain always proceeds smoothly, and you can then easily separate the solids as well!
Due to these properties, barley is the base malt of every beer. Other types of malt are used because they impart certain flavors, such as wheat malt, rye malt, and oat malt. Usually, at least 50% of the malt used is barley malt; however, typically between 85% and 100% of the malt used is barley.