Quality Control in Brewing

## Science Meets Tradition

Modern sake brewing is as much science as craft. Even the most tradition-bound {{glossary:kura}} employs laboratory analysis and sensory evaluation to monitor quality at every stage. This rigor ensures that the brewer's artistic vision is realized consistently.

## Rice Analysis

Quality control begins with incoming rice. Moisture content (target: 14-15%), grain size, crack rate, and shinpaku quality are all measured. Rice that fails to meet specifications is returned or assigned to lower-grade production. Polishing quality is verified by sampling grains at regular intervals.

## Koji Evaluation

Finished {{glossary:koji}} is assessed for enzyme activity (amylase and protease levels), moisture content, and physical appearance. Laboratory assays measure saccharification power — the amount of glucose produced per unit of koji per hour. These numbers guide the brewer's decisions about moto and moromi formulation.

## Fermentation Monitoring

During the 18-32 day moromi fermentation, the brewer tracks specific gravity (Baume), temperature, acidity, and amino acid level daily. Plotted on a chart, these data points form the fermentation curve, which the {{glossary:toji}} compares to the target profile and adjusts by raising or lowering the tank temperature.

## Sensory Evaluation

No instrument can replace the human palate. Brewery staff conduct regular sensory panels throughout production, tasting moromi samples, freshly pressed sake, and matured product. Professional competitions and inter-brewery tasting groups provide external benchmarks for quality.

## Traceability and Records

Every batch is logged with complete production records: rice source, polishing ratio, koji type, yeast strain, moto method, fermentation data, pressing date, and storage conditions. This traceability enables root-cause analysis when issues arise and provides the data foundation for continuous improvement.