If you’ve ever seen “sur lie” on a bottle of Muscadet, or read that a Champagne spent years “on the lees”, you may have wondered what lees actually are. Wine lees are the sediment left behind after fermentation, made mostly of dead yeast cells that settle at the bottom of the tank or barrel. They may not sound appealing, but many of the world’s great white and sparkling wines owe their creamy texture and toasty aromas to them.
What are wine lees made of?
During fermentation, yeast feeds on the sugar in the grape juice and turns it into alcohol and carbon dioxide. Once the sugar runs out, the yeast dies and sinks to the bottom of the vessel, along with other solid particles from the grapes.
Lees are mainly made of:
- Dead yeast cells
- Small pieces of grape skin, pulp and seeds
- Tartrate crystals, natural salts from the grapes
You can find out more about each step of fermentation in our guide on how wine is made.
What’s the difference between gross lees and fine lees?
Winemakers talk about two types of lees, depending on the size of the particles and how quickly they settle.
Gross lees are the heavy, coarse particles that drop to the bottom within a day or so of fermentation. They include grape fragments and clumps of yeast, and can give the wine bitter or unpleasant flavours. Winemakers usually remove them by racking, which means gently moving the wine into a clean vessel and leaving the sediment behind.
Fine lees are much smaller particles, mostly dead yeast, that settle slowly over the following weeks. These are the lees winemakers choose to keep in contact with some wines, to add flavour and texture.
What does ‘on the lees’ or ‘sur lie’ mean?
A wine aged “on the lees” has been left in contact with its fine lees after fermentation, rather than being separated from them straight away. “Sur lie” is simply the French for “on the lees”, and you’ll often see it on labels from France.
This contact can last from a few months to several years, depending on the style of wine. Lees ageing is also called lees contact, and it’s one of the winemaker’s main tools for shaping a wine’s texture.
How is wine aged on lees?
In tank or barrel
For still wines, the wine simply rests on its fine lees in a stainless steel tank or an oak barrel. Over time, the dead yeast cells slowly break down and release compounds into the wine, a process called autolysis. This is what gives lees-aged wines their rounder, creamier feel.
Lees stirring (bâtonnage)
Some winemakers stir the lees back into the wine from time to time, a technique called lees stirring or bâtonnage in French. Traditionally, this is done with a stick (a “bâton”) through the opening of the barrel. Stirring keeps the lees in contact with more of the wine, which boosts their effect on flavour and texture.
In the bottle
For traditional-method sparkling wines, like Champagne, the second fermentation takes place inside the bottle. The yeast that creates the bubbles dies and stays in the bottle, so the wine ages on its lees for months or even years. The lees are then gathered in the neck of the bottle, a step called riddling, and removed by disgorgement before the wine is sold. Our guide on how sparkling wine is made explains each step.
What do lees do to a wine?
Lees ageing changes a wine in several ways:
- Texture: a rounder, fuller body and a silky, creamy feel in the mouth
- Aromas: notes of bread, brioche, toast, biscuit, nuts and butter
- Freshness: lees absorb oxygen, which helps protect the wine from oxidation
- Complexity: more layers of flavour, especially as the wine ages
Lees ageing needs care, though. Left unattended, lees can give off sulphur compounds that smell of struck matches or rotten eggs, which is one reason winemakers stir them or taste the wine regularly. Find out more about these faults in our guide on how to tell if a wine is bad.
Which wines are aged on lees?
Lees ageing is used all around the world, mostly for white and sparkling wines. Our guide on how white wine is made explains where it fits in the process.
Muscadet Sur Lie
Muscadet, from the western end of the Loire Valley, is the most famous example. A Muscadet labelled “Sur Lie” spends the winter on its lees and is bottled straight from them. This gives a light, crisp wine more texture and a slightly yeasty, savoury character.
Burgundy and Chardonnay
Many white Burgundies are aged in barrel on their lees, often with bâtonnage, which adds richness and nutty, buttery notes. Winemakers in California and elsewhere use the same method with Chardonnay.
Champagne and traditional-method sparkling
Lees ageing is essential to Champagne. Non-vintage Champagne must age for at least 15 months in the cellar, including 12 months on its lees, and vintage Champagne for at least three years. Many producers age their wines much longer, which is where Champagne’s brioche and toasty aromas come from.
Other white wines
Some producers also age Sauvignon Blanc, Riesling, Albariño and other varieties on their lees, to soften their acidity and add texture.
What food goes with wines aged on lees?
Lees-aged wines are very food-friendly, thanks to their texture and savoury notes. They pair especially well with creamy sauces and buttery flavours.
Sparkling wines
Sparkling wines aged on lees are fantastic with raw fish such as sushi, sashimi or ceviche, as their acidity balances the fresh, citrusy flavours. They’re also a classic match for smoked salmon.
White wines
Lees-aged whites pair wonderfully with shellfish like oysters, mussels, clams and scallops. Their fuller body and toasty notes also suit a creamy risotto, pasta with rich sauces like carbonara, or soft cheeses like Brie and Camembert. And for a Sunday lunch, try one with roast chicken.
Is sediment in my bottle the same as lees?
Not always. Most wines are separated from their lees before bottling, so the sediment you find in your glass usually comes from something else:
- Tartrate crystals: small, clear crystals that look like sugar or glass, often in white wines that have been very cold. They’re sometimes called “wine diamonds”.
- Red wine sediment: dark deposits of tannins and colour that form as red wines age.
- Lees: some unfiltered wines, especially natural wines, and many pét-nats (naturally sparkling wines) are bottled with a little of their lees, which makes them slightly cloudy.
All of these are completely harmless. If you’d rather not have them in your glass, stand the bottle upright for a few hours and pour slowly, or use a decanter. Our guide on how to serve wine explains how to decant.
FAQ
Is it safe to drink wine lees?
Yes, lees are completely safe to drink, as they’re simply dead yeast and grape particles. They can taste a little gritty or bitter, though, so most people prefer to leave them in the bottle.
Does Champagne have lees?
Champagne ages on its lees in the bottle, but they’re removed by disgorgement before it’s sold, so the finished wine is clear. Find out how it’s done in our guide on how sparkling wine is made.
What does sur lie mean on a label?
“Sur lie” is French for “on the lees”. It means the wine was aged in contact with its lees before bottling, which gives it more texture and flavour.
Are lees and sediment the same thing?
Lees are one type of sediment, formed during and after fermentation. The sediment in an older red wine, or the crystals in a cold white, are something different, but just as harmless.
