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Aeration is the practice of moving large volumes of air at low flow rates sufficient to cool all beans within a bin. With the proper flow rate, relative humidity and temperature, stored bean quality can be stabilized. Aeration prevents moisture migration and also reduces mold growth since mold activity decreases rapidly at temperatures below 70°F. Most field and storage molds become inactive at 50°F. Aeration can also reduce, but not eliminate, musty odors and off‐flavors. It has been demonstrated that an airflow rate of 0.1−0.2 cubic feet per minute is desirable for on‐farm storage facilities. Specifically, any bean storage of greater than 1,000 bushels should be equipped with an integral aeration system (Maddex 1978).

Beans that are not sufficiently field‐dried at harvest are unsuitable for long‐term storage without artificial drying. This may be achieved by passing large volumes of warm air (generally between 105°F and 145°F) through the bean mass. Artificial drying of beans requires strict monitoring of the drying conditions. Excessively high drying temperatures will damage the external appearance (seed coat fracture and discoloration) and alter the inherent starch and protein functional properties. Beans may be dried in small batch lots on ventilated wagons or more commonly in designated drying bins. These batch systems establish moving air through static beans and will adequately remove moisture without seed coat damage. Rapid drying conditions can also produce case hardening in which seed surfaces are differentially dried relative to internal seed tissue, thereby resulting in excessive stress and increased seed coat damage (McWatters et al. 1988). Drying too slowly can create conditions favorable for mold growth, resulting in deterioration of quality.