What is the minimum koji level required for Tokutei Meishoshu?

The minimum koji level required for Tokutei Meishoshu is 15%. Tokutei Meishoshu refers to a class of sake that includes premium designations, which must meet certain criteria in order to achieve this status. One of these criteria is the amount of koji, the mold used in the fermentation process, which affects the flavor, aroma, and overall quality of the sake. A koji level of at least 15% ensures a sufficient concentration of enzymes that help convert starches to sugars, leading to a more refined sake. This higher koji level is indicative of a meticulous brewing process and contributes to the overall quality attributes expected from Tokutei Meishoshu.

The other options suggest levels that do not meet the defined standards for this classification. A level below 15% could lead to sake that does not fully develop the complexity and desirable characteristics associated with premium sake. Thus, the 15% koji level is a critical threshold that upholds the refined and quality-driven nature of Tokutei Meishoshu.