is the inability of mature, viable barley to germinate under favorable conditions. Dormancy is a natural phenomenon in plants that protects seeds from germinating during seed development, which can be advantageous for maltsters after a wet harvest. However, it can be a disadvantage when dormant barley fails to germinate in the malthouse. Barley must germinate vigorously and quickly when steeped during malting if quality, trouble-free malt is to be produced. Malt containing dormant kernels produces less malt extract and more wort beta-glucan, resulting in less beer and problems with poor lautering and beer filtration in the brewhouse. The degree of dormancy in barley varies with variety and storage conditions but weather during harvest and grain silo filling is a significant factor. Barley grown under cool, wet conditions is more dormant than barley grown under hot, dry conditions. The physiological basis of dormancy is poorly understood but has been attributed to the physiological state of the embryo, availability of oxygen to the embryo, and microbial load on the barley. Dormancy will break naturally, given sufficient storage time, but can be hastened by carefully drying barley after harvest to 11%–12% moisture, followed by 2 weeks of warm storage at 25°C–30°C (77°F–86°F) and then cooling to a final storage temperature of less than 17°C (62.5°F). Dormancy is measured by comparing results from a standard germination test (germination energy) to germination results after treatment with hydrogen peroxide (germinative capacity). Dormancy can also be determined by staining longitudinally split kernels with tetrazolium.

See also germination, malting.