Lees ageing
Lees ageing is a winemaking practice in which wine is matured in contact with its lees, the sediment composed primarily of dead yeast cells and other solids remaining after alcoholic fermentation. This technique influences mouthfeel, aroma development and, in some cases, wine stability, and is widely used in the production of both still and sparkling wines.[1]
Definition and composition of lees
Lees consist mainly of yeast cells that have completed fermentation, along with grape solids, tartrates and other particulate matter. Fresh, fine lees are generally distinguished from coarse lees, which contain heavier solids and are usually removed earlier to avoid reductive or microbial faults. Lees ageing typically refers to extended contact with fine lees rather than gross sediment.[2]
Autolysis and chemical effects
During lees ageing, yeast cells undergo autolysis, a slow enzymatic breakdown that releases polysaccharides, amino acids and other compounds into the wine. These substances contribute to increased viscosity, improved mouthfeel and a perception of roundness. In sparkling wines, autolysis is also responsible for characteristic aromas associated with bread, biscuit and pastry notes.[3]
Lees contact can also influence protein and tartrate stability, helping to reduce haze formation and contributing to overall wine stability under certain conditions.[4]
Winemaking practices
Lees ageing may be carried out with or without periodic stirring, known as bâtonnage. Stirring redistributes the lees throughout the wine, enhancing extraction of lees-derived compounds but also increasing oxygen exposure. Decisions regarding duration, temperature and stirring frequency are stylistic and depend on grape variety, wine style and desired sensory outcome.[5]
Extended lees ageing is fundamental to traditional-method sparkling wines, where bottles remain in contact with lees for months or years before disgorgement. In still wines, particularly certain whites, lees ageing is used more selectively to enhance texture without obscuring varietal character.
Regional and stylistic use
Lees ageing is closely associated with wines such as Champagne and other traditional-method sparkling wines, as well as still wines from regions like Muscadet, where sur lie ageing is a defining stylistic requirement.[6]
Outside Europe, lees contact is widely employed in both Old World and New World winemaking, particularly for varieties such as Chardonnay, where texture and complexity are key stylistic goals.
Regulatory considerations
The OIV recognises ageing on lees as an established oenological practice and provides guidance on its application within broader frameworks of wine production and stability management.[7]
See also
References
- ↑ Jancis Robinson, Oxford Companion to Wine, Oxford University Press, 17 Sept. 2015. ISBN 9780198705383.
- ↑ Ribéreau-Gayon et al., Handbook of Enology, Vol. 2, Wiley, 2006, ISBN 978-0470010396.
- ↑ PhD Jackson, Ronald S., Wine Science: Principles and Applications, Academic Press Inc, 14 April 2020. ISBN 9780128161180.
- ↑ Andrew L. Waterhouse, Understanding Wine Chemistry, Wiley, 19 Aug. 2016. ISBN 9781118627808.
- ↑ Peynaud, Knowing and Making Wine, Wiley, 1984, ISBN 978-0471881491.
- ↑ Stevenson, The Sotheby’s Wine Encyclopedia, DK, 2011, ISBN 978-0756686840.
- ↑ OIV, “Ageing on lees”.