The moisture redistribution period is called tempering. Rate of tempering drops slightly as temperature drops. A 10 F drop in temperature increases tempering time by 17 minutes. In California, tempering times are often about 24 hours because large batches, requiring about 8 hours to pass through the dryer are common. How to reduce fissuring 1 .
Varieties differ in their susceptibility to fissuring.
Medium grain rice tends to be more susceptible to fissuring compared with long grain rice. But even within a type of rice there can be significant differences. Varieties with lower range of maturity are subject to less fissuring. Breeders, though, select rice with some variation in maturity to spread pollination over a number of days so that adverse weather conditions at flowering have less potential to cause significant yield losses. Varieties that are susceptible to fissuring must be handled with particular care to minimize damage.