Lees

Lees are the deposits of dead yeast cells, grape solids, and other particles that settle at the bottom of a vessel during and after fermentation. The term derives from the Old French *lie*, itself from the Latin *levare*, meaning "to lift" or "to rise"^[1]. In winemaking, lees are both a by-product and an important tool, influencing the flavour, aroma, and texture of wines when handled in specific ways.

Background

Lees naturally form during alcoholic fermentation as yeast consumes sugars and multiplies, eventually dying off and settling along with fragments of grape skin, pulp, and tartrates^[2]. Winemakers historically regarded them as waste to be separated from the wine through careful racking. Over time, however, their role in enhancing quality became more widely recognised.

Composition and Characteristics

Lees are typically divided into two categories. "Gross lees" consist of coarse grape matter and heavier sediment that can lead to undesirable odours if left too long in contact with wine. "Fine lees" are made up mainly of yeast cell walls and lighter deposits, which can interact beneficially with the wine through autolysis — the gradual breakdown of yeast releasing compounds that contribute to complexity, texture, and stability^[3].

Role in Winemaking

Removal of lees through racking is standard practice to avoid spoilage, particularly with gross lees. Yet, deliberate contact with fine lees has become central to certain winemaking traditions. As yeast breaks down, mannoproteins and amino acids are released, enhancing mouthfeel and contributing savoury or nutty notes to the finished wine^[4]. Some winemakers periodically stir the lees, a process known as bâtonnage, to increase the extraction of these compounds and give the wine additional richness.

Use in Different Wine Styles

Extended lees ageing is integral to sparkling wine production by the traditional method, particularly in Champagne, where wines must legally remain on lees for a minimum period before release. This practice yields distinctive aromas of brioche, biscuit, and creaminess associated with mature sparkling wines^[5].

Lees also play a role in certain still wines. In the Loire, Muscadet Sur Lie is bottled directly off the lees to preserve freshness and impart subtle yeasty complexity. In Burgundy and elsewhere, Chardonnay is frequently aged on lees, with or without bâtonnage, to add depth and balance to the variety’s natural acidity^[6].

References

↑ Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015, ISBN 978-0198705383.
↑ Zoecklein, Fugelsang, Gump & Nury, Wine Analysis and Production, Springer, 1999, ISBN 978-0834217011.
↑ Jackson, Wine Science: Principles and Applications, 5th ed., Academic Press, 2020, ISBN 978-0128161180.
↑ Peynaud, Knowing and Making Wine, Wiley, 1984, ISBN 978-0471881491.
↑ Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015, ISBN 978-0198705383.
↑ Stevenson, The Sotheby’s Wine Encyclopedia, 5th ed., DK, 2011, ISBN 978-0756686840.

[1] Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015, ISBN 978-0198705383.

[2] Zoecklein, Fugelsang, Gump & Nury, Wine Analysis and Production, Springer, 1999, ISBN 978-0834217011.

[3] Jackson, Wine Science: Principles and Applications, 5th ed., Academic Press, 2020, ISBN 978-0128161180.

[4] Peynaud, Knowing and Making Wine, Wiley, 1984, ISBN 978-0471881491.

[5] Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015, ISBN 978-0198705383.

[6] Stevenson, The Sotheby’s Wine Encyclopedia, 5th ed., DK, 2011, ISBN 978-0756686840.

[1]

[2]

[3]

[4]

[5]

[6]