noun, plural /liːz/

Lees

The sediment of dead yeast cells, grape pulp fragments and tartrate crystals that collects at the bottom of a wine vessel after fermentation. Ageing wine in contact with lees (sur lie) contributes texture, creaminess and autolytic complexity.

Where lees come from

Fermentation converts grape sugar into alcohol and carbon dioxide using yeast — either naturally present on grape skins (wild/ambient yeast) or inoculated by the winemaker. Once the yeast has consumed all available sugar (or the alcohol rises high enough to inhibit further activity), the cells die and sink to the bottom of the vessel. This sediment is the lees. During active fermentation, the lees are kept in suspension by the movement of CO2 gas; once fermentation stops, they gradually settle.

The decision of when to rack the wine off its lees — and how much fine lees to retain — is one of the fundamental winemaking choices that shapes texture and complexity. For how fermentation itself works, see the fermentation glossary entry.

Sur lie ageing in practice

The most famous application of lees ageing is Champagne. Non-vintage Champagne must age on its lees for a minimum of 15 months after the second fermentation; vintage Champagne for a minimum of 36 months. Prestige cuvees (Krug Grande Cuvee, Dom Perignon) are often aged for six to ten years on lees before disgorgement. The result is the characteristic Champagne complexity: brioche, toast, almond, and a creamy mousse. For a full account of the method see the sparkling methods guide.

In still wines, sur lie ageing is most associated with white Burgundy and Muscadet. Winemakers typically retain fine lees in barrel or tank after racking off gross lees, sometimes stirring with a batton (battonage) to maintain contact. The technique adds a creamy texture and a savoury, nutty complexity that extends the palate length. For ageing vessels and their effects, see the wine ageing methods guide.

Lees meaning, lees wine ageing and batonnage meaning

The lees meaning in winemaking refers to the sediment of dead yeast cells that settles after fermentation. Lees wine ageing — keeping wine in contact with this sediment — is a deliberate technique used to add texture, creaminess and autolytic complexity. The batonnage meaning is the periodic stirring of these lees, typically in barrel, to maximise contact between the yeast sediment and the wine. Batonnage releases polysaccharides and mannoproteins from the dead yeast cells, coating the palate and producing the characteristic bready, biscuity, nutty richness associated with fine white Burgundy and Champagne. The WSET winemaking curriculum covers lees wine ageing and batonnage as key techniques for building texture in white wines, and Jancis Robinson's Oxford Companion to Wine provides extensive detail on the biochemistry of yeast autolysis during lees contact.

Sources: Comité Champagne (lees ageing regulations for Champagne); AWRI (yeast autolysis and lees interaction research); UC Davis Viticulture & Enology (fermentation science). Last updated: 2026-10-17. Corrections via the contact form.

Questions

About lees.

What are lees made of?

Lees consist primarily of dead yeast cells — the microorganisms that consumed grape sugar during fermentation and then died once the alcohol level rose high enough to kill them. Lees also contain grape pulp fragments, seeds and skins (in the case of red wine), tartrate crystals (cream of tartar, harmless salt deposits) and protein-polysaccharide complexes. The sediment you see in an unfiltered bottle of wine is a form of lees. "Fine lees" refers to the finer, lighter particles that remain in suspension longer; "gross lees" (or "heavy lees") refers to the coarser, denser material that settles first. Winemakers typically rack off gross lees quickly and retain fine lees for flavour development.

What is sur lie ageing and what does it taste like?

Sur lie (French: "on the lees") means leaving wine in contact with its fine lees after fermentation rather than racking it off immediately. As the dead yeast cells break down (a process called autolysis), they release polysaccharides, mannoproteins and amino acids into the wine. These compounds coat the palate and produce a characteristic creamy, rounded, bready texture sometimes described as "leesy" or "yeasty." Muscadet Sevre et Maine sur Lie is the classic example — the appellation legally requires a minimum period on lees and the wines develop a distinctive nutty, saline creaminess. Champagne's extended lees contact (minimum 15 months for non-vintage, 36 months for vintage) produces the famous brioche and toast character. White Burgundy and Chardonnay producers often use sur lie ageing with battonage to build texture.

What is battonage?

Battonage (French, from "baton" — a staff or rod) is the practice of stirring the lees periodically while wine is ageing in barrel or tank. This keeps the fine lees in suspension, increasing contact between the lees and the wine, and accelerating the release of textural compounds. Battonage is particularly common in white Burgundy production, where a winemaker may stir the barrel weekly or monthly during the ageing period. The technique adds creaminess and body, and helps prevent the formation of reductive off-aromas that can develop in stagnant, unworked lees. For the broader ageing context, see the wine ageing methods guide.

Does all wine age on its lees?

No. Many wines are racked off their lees promptly after fermentation — either to prevent off-aromas from lees breakdown or because the winemaker wants to preserve fresh, pure fruit character. White wines intended for early drinking and aromatic clarity (Sauvignon Blanc, Pinot Grigio, basic Prosecco) are often racked and filtered quickly. Sur lie ageing is a deliberate stylistic choice, used for wines where textural complexity and autolytic character are desired: aged Chardonnay, Champagne, Muscadet and some aged Riesling. Red wines also age on their lees to varying degrees, though the effect is less prominent because tannin provides structural complexity.

What is the difference between lees meaning in Champagne and still wine?

In both Champagne and still wine, lees meaning refers to dead yeast cells — but the context and effect differ. In Champagne (traditional method), the lees from the secondary fermentation in the bottle are trapped with the wine for months or years: minimum 15 months for non-vintage, 36 months for vintage, and often 6-10 years for prestige cuvées. This extended lees contact produces the characteristic brioche, toast, almond and biscuit complexity of fine Champagne. The lees are eventually removed during disgorgement. In still wine, lees wine ageing occurs in barrel or tank after primary fermentation. The winemaker may stir the lees (batonnage) to accelerate the release of textural compounds. Still wine lees ageing produces a creamier, rounder mouthfeel and savoury complexity — most associated with white Burgundy and Muscadet Sur Lie. Batonnage meaning is specifically this stirring practice — from the French "bâton" (staff or rod) used to reach into the barrel. See the sparkling methods guide for how lees contact differs between traditional method and tank method production.

Is the sediment in my wine bottle lees — and is it safe to drink?

The sediment in a bottle can be lees or tartrate crystals (both harmless) or, in aged red wine, polymerised tannin-pigment deposits. All are safe to consume but affect texture and may add bitterness if poured into the glass. The standard approach is to stand the bottle upright for 24 hours before opening, allowing sediment to settle, then decant carefully. The decanting explained guide covers this procedure step-by-step.