Probably all of you have heard that ready beer is (most often) the result of combining three ingredients - water, hops and malt. As for the former two, they occur naturally and can be used unchanged (although there are processes that make them more efficient). Malt, on the other hand, is a grain of cereal, which only undergoes certain processes takes on completely new values and although it does not have to differ in appearance, its chemical composition and density differ diametrically from the standard grain. This process is called malting.
What is the malting process?
The malting process consists in stopping the germination of the grain at the right moment so that as much sugar is retained inside as possible. If interrupted too early or too late, it will not give the brewer the desired effects, and the beer brewed with such malt will not give the expected results. The cereal most often subjected to the malting process is barley.
What is the purpose of malting cereals?
The most important purpose of malting cereal grains is to convert the starch in its internal structure into sugar.
To understand this better, we need to know the structure of a single grain. As you can see in the attached picture, the grain is completely surrounded by the husk. There is a spire at its base and a root underneath it. The interior of its main part - the endosperm - is surrounded by a aleurone layer. And it is these last three building blocks that will play a major role in converting starch into sugar.
With the right amount of water, the seed begins to sprout. That's when all the magic begins.
During germination, enzymes are released from the aleurone layer, which break down the protein-carbohydrate matrix surrounding the endosperm.
The endosperm, in turn, is an energy store for the barley grain. Its cells contain starch particles, which - when the embryo begins to grow - turns into sugar. This is due to the aforementioned enzymes which are capable of destroying the starch-containing cell walls and then converting this starch into sugar.
This sugar is needed by the plant to grow, and the previously mentioned stopping the malting process at an inappropriate time will result in not having enough sugar in the grain of the malt - either because not all of the starch elements have turned into sugar, or because the plant has used it up too much.
What does malting look like in practice?
The first stage of malting is soaking the grains. This one absorbs a lot of water, but the grain increases in weight by up to about 50% of its original weight. Then, the already soaked grain is sent to a room where it germinates at appropriate temperatures. It is worth noting that germinating grains often have to be turned over because they generate natural heat.
Whether the malt is ready for the next stage, home brewers can check in two ways. The first is to measure the length of the sprout protruding from the grain. It should be between 75% and 100% of the grain length. The second is to squeeze the sprouted grain with your fingers. It can then be determined which areas of the grain have not softened. However, this method requires a lot of experience.
The final stage is drying, which usually begins at around 50 ° C. After one day, its humidity drops to approximately 20%, and further drying takes place at higher temperatures, and the subsequent color and taste of the malt depends on them. Then the rootlets are removed.
The malt prepared in this way is ready to be brewed from it!
Why barley malt?
Barley malt has become very popular in brewing because it is surrounded by a husk which acts as a natural filter in the process of cooling the wort.
Other popular malts are wheat and rye malts, but they play a marginal role in world beer production.
To sum up - the malting process allows us to convert the starch contained in the grain into sugar, thanks to which we can - with the help of water at the right temperature - extract it, and it will become food for the yeast, which will turn it into alcohol.
The malting process can be carried out by any brewer at home, but it requires appropriate conditions, equipment and place. Therefore, it is much easier to buy ready-made malt.