When there is no risk of insect infestation, cereals can be stored at 20°C for a whole year without any deterioration in technological quality or germination capacity, provided they are dry from the start.
It is possible to predict the shelf life without risk of spoilage by combining the temperature and moisture content of the grain at the time of storage. A quick estimate of the risk-free shelf-life (RHSL) for cereals can be made using a simple nomogram (figure 15).
On each side of the circle are two scales: grain temperature and moisture content (at binning). On the central vertical diameter is the safe storage time scale (in days). By linking grain temperature and moisture content (cereals only, excluding malting barley) with a straight line, the intersection with the vertical scale gives an estimate of the risk-free shelf life (RFSL). With the red line (joining 14.5% t.e. and 25°C), the RFSL is 60 J.; with the blue line (joining 14.5% t.e. and 7°C), the RFSL is 450 J.
For malting barley (a special case of a cereal that must germinate 95% of the time), it is imperative to preserve germinative capacity, so risk-free storage times are reduced for storage temperatures above 20-22°C and water contents above the critical threshold of 14% (table 2).
