Tempering

When the drying of grain is temporarily stopped the moisture within the grain equalizes due to diffusion. When drying is restarted, the drying rate becomes higher compared to continuous drying. The process of stopping intermittently is called tempering. In addition during tempering the moisture differences between grains equalize. Tempering therefore also ensures that moisture gradients in the grain bulk that develop during drying in certain dryer types are minimized.

To maintain grain quality, including a tempering period is recommended to allow for redistribution of internal moisture in the grain. In modern re-circulating grain dryers, grain is not dried continuously but goes through a cycle of drying followed by tempering. This improves drying rates, grain quality and reduces energy costs.

http://www.knowledgebank.irri.org/rkb/drying-basics/the-dryi...

The three-stage drying process employed by Bühler is extremely
fast and nevertheless gentle to the product. It reduces moisture
content from approx. 30 % to about 12 %. Different temperature
settings and „rest periods“ in so-called tempering bins increase
throughput capacity without any damage to the product.

Pages 14 and 15

https://f69aa27b9b6c6702e27b-ffbfdeddb5f7166a1729dfea28599a6...