Relative humidity

Relative humidity is an index that shows what proportion of the saturated water vapor pressure at a given temperature is represented by the amount of water vapor actually present in the air. It is calculated by dividing the actual water vapor pressure by the saturated water vapor pressure and multiplying the result by 100, and is expressed as a percentage (%). In sake production and storage, relative humidity is very important: excessive humidity encourages the growth of mold, while humidity that is too low can adversely affect the quality of the sake. Managing relative humidity is therefore an essential factor in maintaining sake quality.