Wine production



YEAST ASSIMILABLE NITROGEN (YAN). A measurement of amino acids and ammonia compounds used by wine yeast during fermentation.

YEAST AUTOLYSIS. A complex chemical process that takes place after fermentation when the wine spends time on the lees (dead yeast cells). Particularly valued in Champagne making where it adds biscuity aromas and gives creamy mouthfeel.

YEAST HULLS. Empty (autolyzed) yeast cell walls.