To what moisture level is rice dried, and why?

The moisture level to which rice is dried for sake production is typically 14-16%. This level is crucial as it helps prevent the rice from rotting and cracking during the storage and subsequent milling processes. Rice that is too moist can develop mold or spoil, compromising the quality of the sake. Furthermore, if rice kernels crack due to excess moisture, they can lead to uneven cooking and poor fermentation, adversely affecting the final product's flavor and quality.

The other moisture levels presented do not serve the same practical purpose. Drier rice, as suggested in other options, would not address the risks of spoilage effectively, and moisture at higher levels may lead to issues with grain integrity and fermentation. Thus, achieving a moisture content of 14-16% strikes a balance that supports safe storage and optimal processing for sake production.