Because the starch in the kernel of the barley grain is not soluble in water, the grain needs to undergo a process called “Malting” to release the starch. Barley grains straight from the fields contain all manners of impurities; therefore before barley is malted it has to be cleaned.
After the initial cleaning, the barley is stored in silos where it undergoes a period of post ripening. After the impurities are removed through sifting and the barley is sorted according to grain size, three processes of the malting process take place: steeping, germinating and kilning.
Steeping is the simple process of increasing the moisture content in the barley grains; it is during this process where the living kernel of the grain absorbs water. The duration of steeping barley is 24 hours, and then the barley kernel germinates.
The main purpose of ger- mination is to form enzymes, which can break down the starch present in the barley kernel, so that it will be soluble. The end result of this pro- cess is what is known as ‘green malt’.
Green malt is then kilned or dried to stop the germination and also to enable storage .The most commonly used drying method is to expose the green malt to hot air (up to 80 °C). It is during this process that green malt develops its colours and flavours. After kilning, the malt can enjoy a rest period of approximately 3 weeks after which it is polished to remove any dust and is ready for brewing.