Acidity
Acidity in wine refers to the concentration and perception of organic acids naturally present in grapes and produced during fermentation. It is a central component of wine tasting, contributing to freshness, balance, and the ageing potential of a wine.[1]
Background
The term derives from the Latin acidus, meaning “sour” or “sharp”. In the context of wine, acidity describes both the measurable presence of acid compounds and the sensory impression they impart. Grapes contain a mixture of organic acids, of which tartaric and malic are most significant, alongside smaller quantities of citric and succinic acids.[2] The concentration of these acids is influenced by grape variety, vineyard location, and harvest conditions, with cooler climates generally producing higher acid levels.
Characteristics
Acidity in wine is usually assessed by two methods: titratable acidity, which measures the total concentration of hydrogen ions, and pH, which indicates the relative strength of acidity.[3] Wines with lower pH values tend to show greater stability and resistance to microbial spoilage.
From a sensory perspective, acidity provides crispness and liveliness, balancing sweetness and softening the perception of tannin. Excessive acidity can render a wine harsh, while insufficient acidity may result in a wine that tastes flat or cloying.[4] High natural acidity also plays a key role in the ability of certain wines, such as Riesling or Champagne, to age gracefully.
Use in winemaking
Winemakers manage acidity both in the vineyard and in the cellar. Harvest timing is crucial, as acid levels decline as grapes ripen. In warmer regions, where natural acidity may be insufficient, acidification with tartaric acid is permitted in many wine laws. Conversely, in cooler climates, deacidification may be used to soften sharp flavours.[5]
Malolactic fermentation, a process in which malic acid is converted to the softer lactic acid, is widely used in the production of red wines and some whites, such as Chardonnay, to reduce sharpness and add complexity. Regional styles are closely tied to acid balance: for example, German Rieslings are prized for their racy acidity, while Mediterranean reds often rely on softer acid structures.
See also
References
- ↑ Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015, ISBN 978-0198705383.
- ↑ Jackson, Wine Science: Principles and Applications, 5th ed., Academic Press, 2020, ISBN 978-0128161180.
- ↑ Iland, Bruer, Edwards, Weeks & Wilkes, Chemical Analysis of Grapes and Wine, Patrick Iland Wine Promotions, 2004, ISBN 978-0958160515.
- ↑ Peynaud, Knowing and Making Wine, Wiley, 1984, ISBN 978-0471881491.
- ↑ Boulton, Singleton, Bisson & Kunkee, Principles and Practices of Winemaking, Springer, 1999, ISBN 978-0834217011.