Grain processing: Kilning process

Malting is a three-step process consisting of steeping, germination and finally kilning. When germination stage is deemed to have lasted long enough, it is stopped by heating the grain in a process referred to as kilning.

The aim is to drive off water until the moisture level in grain is below 5%, when the metabolism of the barley will be heated and the product stabilized. The objective is to achieve development of malt colors and flavors.

This requires intense heat, yet the malt enzymes, which heat tends to inactivate, must be conserved The kiln has provision of gradual temperature increase and air circulation, and energy is conserved to the maximum extent possible.

The kilning is usually done from 16-40 h with gradual increase in the temperature. In the kilning process, the breakdown products (amino acids and sugars) released from proteins and carbohydrates during germination meld to form so-called melanoidins, which are colored.
Grain processing: Kilning process