Glycerol

Glycerol (also known as glycerine) is a naturally occurring polyol compound present in wine. It is produced primarily during fermentation and plays a role in shaping the texture and perceived body of wines.^[1]

Background

Chemically, glycerol is a sugar alcohol formed as a by-product of yeast metabolism during alcoholic fermentation. Its concentration in wine usually ranges between 5 and 15 g/L, although higher levels may occur depending on grape ripeness, must composition, and winemaking techniques.^[2] While not a primary flavour component, it contributes significantly to wine’s overall balance.

Sensory Characteristics

Glycerol is associated with sensations of roundness, smoothness, and viscosity on the palate. It can enhance the impression of sweetness even though it is less sweet than glucose or fructose. Although sometimes linked to the “legs” or “tears” observed on the inside of a wine glass, these are predominantly the result of ethanol concentration and surface tension effects rather than glycerol content.^[3]

Role in Winemaking

The production of glycerol depends on yeast strain, fermentation temperature, and oxygen availability. Warmer fermentations and specific yeast varieties can lead to increased levels, although excessive stress during fermentation may also elevate glycerol concentrations. Enologists may consider glycerol as part of a wine’s structural elements, but its presence alone is not a reliable indicator of quality.^[4]

Analytical Aspects

Glycerol is routinely measured in wine laboratories as part of chemical composition analysis. Its levels are not subject to legal limits, but it provides useful data for monitoring fermentation and for research into mouthfeel and balance.^[5]

References

↑ Jackson, Wine Science: Principles and Applications, 5th ed., Academic Press, 2020.
↑ Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015.
↑ Ribéreau-Gayon et al., Handbook of Enology, Vol. 2: The Chemistry of Wine, Wiley, 2006.
↑ Zoecklein et al., Wine Analysis and Production, Springer, 1999.
↑ Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015.

[1] Jackson, Wine Science: Principles and Applications, 5th ed., Academic Press, 2020.

[2] Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015.

[3] Ribéreau-Gayon et al., Handbook of Enology, Vol. 2: The Chemistry of Wine, Wiley, 2006.

[4] Zoecklein et al., Wine Analysis and Production, Springer, 1999.

[5] Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015.

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