🍷 Glycerol

Glycerol is a faintly sweet substance formed during the fermentation of wine. It gives the wine a smooth, oily feel and softness.

When yeast turns sugar into alcohol, it also makes a little glycerol. There are usually a few grams per litre in wine. It is neither sugar nor alcohol but a separate substance. It tastes slightly sweet and makes the wine feel more rounded and fuller. Glycerol is tied to the idea of a wine's body: it is thought to add body, though the effect is smaller than many believe.

Wine taste is shaped not just by glycerol but also by alcohol, sugar, acids and tannins. More glycerol is formed in wine from very ripe grapes and under certain fermentation conditions, for example high temperature. In the glass people sometimes look for it in the "tears" running down the side, but tears mostly depend on alcohol. Glycerol is harmless and naturally present in all wines. It is also an ingredient in many foods. For wine lovers it is one of the subtle features that set a soft wine apart from a hard one.