ABSTRACT
The changes encountered in musts and wines during storage in barrel, tank, carboy or bottle due to microbial activity can be summarized as follows:
Changes due to yeasts: a) spoilage by flor or flowering yeast b) unwanted second fermentations (or
re-fermentation) c) hydrogen sulfide production (odor
of rotten eggs, garlicky odors) and offensive odors of dregs.
