Glycerine
Also called glycerol, glycerine is a colorless, odorless, slightly sweet, oily substance that is a minor by-product of fermentation. Though often commented on by tasters, glycerine probably makes no more than a negligible contribution to a dry wine’s viscosity, and it is not responsible for a wine’s so-called “legs” or “tears.” The wines with the highest glycerine levels are sweet botrytized wines. In these wines, glycerine may contribute slightly to the wine’s sweetness and unctuous feel.