Oak ageing
‘’‘Oak ageing’’’ is a winemaking practice in which wine is matured in oak barrels to enhance its flavour, texture, and aromatic complexity. This process allows for controlled exposure to oxygen and the gradual integration of compounds such as tannins, vanillin, and lactones from the oak itself. Oak ageing is employed in the production of both red and white wines, and the choice of oak type, barrel size, and ageing duration can significantly influence the final character of the wine.
Definition
Oak ageing involves storing wine in barrels made from oak wood, typically either from French or American sources. The process serves both as a vessel for maturation and as an active contributor to a wine’s development. Oak barrels allow for slow oxygen exchange, which can soften tannins in red wines and stabilise colour, while also contributing desirable flavours such as spice, smoke, vanilla, and toast[1].
The influence of oak depends on several factors, including the age of the barrel (new or used), the level of toast applied to the interior, and the duration of the ageing period. New barrels impart stronger flavour characteristics, while older barrels contribute more subtle oxygenation with less aromatic influence[2]. The size of the barrel also matters: smaller barrels increase surface contact and enhance oak extraction, while larger vessels result in gentler effects.
Relevance in Wine
Oak ageing plays a central role in shaping the structure, texture, and flavour profile of many wines, particularly full-bodied reds and select whites. In red wines, oak contributes to the polymerisation of tannins, which can enhance mouthfeel and reduce astringency over time[3]. In white wines, especially Chardonnay, oak can add richness and layers of complexity, often complementing techniques such as malolactic fermentation and lees stirring.
Beyond sensory attributes, oak ageing also serves a technical function in allowing micro-oxygenation, which can help stabilise a wine’s phenolic structure and colour[4]. However, the practice requires skill and balance: excessive oak can dominate varietal character, while too little may leave the wine underdeveloped. As such, oak is often viewed as a winemaker’s tool — one that can either elevate or overwhelm, depending on its application.
Use and Geography
The use of oak in winemaking is widespread, but styles and preferences vary significantly by region and tradition. French oak, particularly from forests like Allier and Tronçais, is known for its fine grain and subtle impact on flavour, often lending notes of spice and toast[5]. American oak, in contrast, tends to impart more pronounced aromas of coconut, vanilla, and dill[6].
Regions such as Bordeaux, Rioja, Barossa Valley, and Napa Valley frequently employ oak ageing for red wines, while white Burgundy and select New World Chardonnays also benefit from oak maturation. Barrels come in various sizes, from small barriques (225 litres) to large foudres, with smaller vessels offering more intense oak influence due to the higher surface area-to-volume ratio.
The choice of oak, toast level, barrel age, and duration of ageing are critical decisions in the cellar. Together, these factors shape not only the sensory profile of the finished wine but also its ageability and market identity.
Effects on Wine Style
Oak ageing can significantly influence a wine’s aromatic and structural profile. New oak barrels, especially those that are heavily toasted, can impart distinctive notes of vanilla, clove, spice, toast, coconut, and even coffee. These flavour compounds stem from the breakdown of lignin and hemicellulose in the wood during toasting[7]. The impact of these compounds tends to be stronger in American oak than in French oak, which is typically more subtle and cedar-like in its aromatic expression.
Structurally, oak ageing can contribute to mouthfeel and perceived body. Barrels allow for gradual oxygen exposure through the wood’s porous surface, promoting the softening of tannins and stabilisation of colour in red wines[8]. Oak contact also encourages polymerisation reactions that enhance roundness and complexity, particularly in fuller-bodied white and red styles.
Repeated use of barrels reduces their aromatic contribution, though neutral barrels may still affect texture and ageing potential through micro-oxygenation. Winemakers may adjust oak impact by varying barrel age, size, toast level, and maturation length to achieve a desired balance in the final wine[9].
See also
References
- ↑ Wine Folly, "Wine and Oak: What Oak Aging Does to Wine", https://winefolly.com/deep-dive/what-oak-aging-does-to-wine/, accessed August 2025.
- ↑ Jamie Goode, The Science of Wine: From Vine to Glass, University of California Press, 2014, pp. 78–81, ISBN 978-0520275751.
- ↑ Emile Peynaud, The Taste of Wine, Macdonald & Co., 1987, pp. 112–115, ISBN 978-0960986821.
- ↑ Jancis Robinson (ed.), The Oxford Companion to Wine, 4th ed., Oxford University Press, 2015, p. 488, ISBN 978-0198705383.
- ↑ Kelli White, “Oak and Wine”, GuildSomm, https://www.guildsomm.com/public_content/features/articles/b/kelli-white/posts/oak-and-wine, accessed August 2025.
- ↑ Wine Folly, “Wine and Oak: What Oak Aging Does to Wine”, https://winefolly.com/deep-dive/what-oak-aging-does-to-wine/, accessed August 2025.
- ↑ Jamie Goode, The Science of Wine: From Vine to Glass, University of California Press, 2014, pp. 190–192, ISBN 978-0520275751.
- ↑ Jancis Robinson (ed.), The Oxford Companion to Wine, 4th ed., Oxford University Press, 2015, p. 485, ISBN 978-0198705383.
- ↑ Emile Peynaud, The Taste of Wine, MacDonald & Co, 1987, pp. 122–124, ISBN 978-0960986821.