The main objective of proper grain storage is to maintain the quality and characteristics that the grain possessed immediately after harvesting and drying. The quality of grain cannot be improved during storage. Grain improperly harvested and dried will remain of low quality no matter how well it is stored. In cereal grains loss in quality and quantity during storage is caused by fungi, insects, rodents and mites. Respiration may, in certain cases, contribute to a loss of dry matter during grain storage. However, the losses due to respiration are minor compared to those caused by living organisms.
Grains reach maturity several days before harvest. To prevent spoilage, harvesting is normally delayed to allow the grain drying time in the field. If barley could be harvested when it reached maturity, rather than having to let it dry in the field, then harvests could be completed earlier with reduced field losses. Tough grain with a moisture content of 15.5 to 17.0% when bin stored may rot. Damp grain with a moisture content greater than 17.1% will rot quickly, often producing enough heat to start a fire. Spoiled grain is useless as feed since there is a risk of toxic chemical build-up during spoilage from aflatoxins, which are produced by soil micro-organisms. Aflatoxins endanger the health of both people and animals. Micro-organic contamination occurs during both the growing season and harvest when dust becomes mixed with the grain. If damp grain is to be stored successfully, you must prevent microorganic growth or kill micro-organisms before growth begins.