Grain safety storage factor—Drying

 The drying of grain is an important condition for ensuring the grain safe storage. It is easy to keep for the dry grain, and it is not easy to breed worms and mildew. Also, dry grain can delay aging and reduce losses, keep the nutrition and eating quality of grain. The wet grain is easy to grow insect and mildew, go bad and agglomerate, even can’t use. In order to ensure the grain safety, the stored grain in rural households should be dried in the sun and then store them as far as possible. The degree of dryness of grain is expressed by grain moisture content. The grain with large moisture content is wet, and the grain with little moisture content is dried. The water content of the grain is expressed as the percentage, that is, the water unit in the 100 units of the grain. For example, the wheat with 12% moisture content means that 50 kilograms wheat contains 6 kilograms water. The paddy with 13% moisture content means that 50 kilograms paddy contains 6.5 kilograms water. The water content can be measured by the scientific instrument –grain moisture tester. Generally， the experienced personnel, such as the quality inspection personnel of the national grain depot, can estimate the grain moisture content accurately by hand scratching and tooth biting.

The wet grain is easy to grow mildew and worms and it's not easy to keep. When the moisture content lowered to the extent that it can be stored safely under the ordinary storage conditions, we call it as safe moisture. Thus, it not only can maintain quality, also not easy to grow worm and mildew.

The safe water content is different according to the different climate, generally, the safe water content is higher in the region which temperature is low. Different varieties grains have different moisture content, such as wheat and paddy, the safe moisture content is higher; while the soybean and peanut is lower.There is only one safe moisture content standard of each kind of grain in the actual grain storage condition, which is that under the normal conditions, to ensure the grain can safely spend the maximum moisture of summer high temperature, as the food safety moisture content standard, as long as the stored grain does not exceed this standard, under the normal condition, the stored grain is safe all the year round. According to the nationwide situation, the safe moisture content of some major grain and oil plants，as shown in the table.


Note: The maximum temperature of oil plants is 250 ℃, when temperature rises, the moisture content decreases accordingly.