Zojo ratio (proportion of rice used for increased-volume sake)

The zojo ratio (増醸割合) is the proportion of white rice used as raw material for zojoshu (増醸酒, increased-volume sake) in sake production, relative to the total amount of white rice used in that sake brewing year. It is expressed as a percentage, and the approval standards set it at 23% or less. Zojoshu is often offered at a more affordable price than ordinary sake, so the proportion of white rice used in the production process is adjusted. This makes it possible to produce sake that keeps costs down while maintaining its flavor and quality.