What is referred to as "Shimpaku" in sake terminology?

"Shimpaku" specifically refers to the core or center of the sake rice grain where the starch is concentrated. This area is crucial for sake brewing as starch is the primary fermentable component that yeast converts into alcohol and other flavor compounds during fermentation. A high proportion of shimpaku in sake rice is desirable because it leads to a more efficient brewing process and contributes to the overall flavor profile and quality of the finished sake.

In the context of sake production, the outer layer of rice, which is primarily composed of proteins and fats, does not play as significant a role in fermentation as the shimpaku does. The fermentation process itself involves transforming sugars from the starch into alcohol and is not directly synonymous with the shimpaku. Finally, specific types of sake yeast are important for determining the flavor and aroma of the sake but are distinct from the structural components of the rice, such as the shimpaku.