Joso
上槽
Définition
The pressing step that separates finished sake from the solid rice lees (sake kasu) after fermentation. Joso methods include machine pressing (Yabuta), traditional box pressing (fune), and gravity drip (shizuku).
En profondeur
Joso timing is one of the most consequential decisions in brewing. Press too early and the sake retains residual sugar and lower alcohol but preserves fresh, vibrant character. Press too late and alcohol rises while off-flavors from yeast stress may develop. The method of pressing also matters: machine pressing is efficient but applies more force, potentially extracting harsh compounds. Fune pressing is gentler, and shizuku — dripping under gravity alone — is the gentlest of all. The three fractions from any pressing (arabashiri, nakadori, seme) have distinct characteristics.