Grain Storage encompasses the methods and structures used to preserve harvested grain for Feed Rations, human consumption, or seed. Proper storage maintains grain quality by controlling moisture, temperature, and pest populations. The goal is to keep grain at moisture content below 14 percent (or 12 percent for long-term storage) and temperature below 15 degrees Celsius (60 degrees Fahrenheit) to prevent mold growth and insect reproduction.
Grain storage has been a central concern of civilization since the Neolithic agricultural revolution. Early storage methods included underground pits, woven baskets lined with mud, and raised granaries. The development of the metal grain bin in the late 19th century and the grain elevator in the early 20th century enabled large-scale centralized storage. Modern hermetic storage technologies, including airtight bags and containers, allow grain to be stored without chemical preservatives.
Metal grain bins are the most common storage structure for large quantities. Bins range from 3 to 15 meters (10 to 50 feet) in diameter, with capacities of 50 to 10,000 bushels. Aeration floors with fans move air through the grain mass to control temperature and moisture. Grain silos, typically concrete or steel, are used for high-moisture storage. On homesteads, grain is commonly stored in galvanized steel trash cans, 55-gallon drums, food-grade plastic buckets, or metal bins in a dry building.
The primary storage pests are granary weevils, rice weevils, lesser grain borers, and Indian meal moths. Prevention methods include cleaning storage containers thoroughly before filling, inspecting grain for existing infestation, and maintaining cool, dry conditions. Diatomaceous earth, applied at a rate of 1 to 2 kilograms per metric ton, kills insects by abrading their exoskeletons. Oxygen reduction through carbon dioxide injection or nitrogen flushing controls insects in sealed containers.
Grain stored at moisture content below 13 percent does not support mold growth or most insect activity. A moisture meter calibrated for the specific grain type provides accurate readings. Temperature monitoring with a thermocouple probe detects hot spots that indicate spoilage or insect activity. The grain mass should be turned or stirred periodically to break up hot spots and equalize moisture.