Lees are deposits of dead

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constit ...

or residual yeast and other particles that precipitate, or are carried by the action of " fining", to the bottom of a vat of

wine Wine is an alcoholic drink typically made from Fermentation in winemaking, fermented grapes. Yeast in winemaking, Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different ...

after

fermentation Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen. In food p ...

and

aging Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In ...

. The same while brewing

beer Beer is one of the oldest and the most widely consumed type of alcoholic drink in the world, and the third most popular drink overall after water and tea. It is produced by the brewing and fermentation of starches, mainly derived from ce ...

at a brewery is known as trub – the same from secondary fermentation of wine and beer are the lees or equally, as to beer only, dregs. This material is the source for most commercial

tartaric acid Tartaric acid is a white, crystalline organic acid that occurs naturally in many fruits, most notably in grapes, but also in bananas, tamarinds, and citrus. Its salt, potassium bitartrate, commonly known as cream of tartar, develops naturally ...

, which is used in cooking and in

organic chemistry Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J ...

. Normally, the wine is transferred to another container (

racking Racking, often referred to as Soutirage or Soutirage traditionnel (meaning racking in French), also filtering or fining, is the process of moving wine or beer from one container to another using gravity rather than a pump, which can be disruptiv ...

), leaving this sediment behind. Some wines (notably

Chardonnay Chardonnay (, , ) is a green-skinned grape variety used in the production of white wine. The variety originated in the Burgundy wine region of eastern France, but is now grown wherever wine is produced, from England to New Zealand. For new ...

, Champagne, and

Muscadet Muscadet ( , , ) is a French white wine. It is made at the western end of the Loire Valley, near the city of Nantes in the Pays de la Loire region. It is made from the Melon de Bourgogne grape, often referred to simply as ''melon''. While mo ...

) are sometimes aged for a time on the lees (a process known as ''

sur lie Lees are deposits of dead yeast or residual yeast and other particles that precipitate, or are carried by the action of " fining", to the bottom of a vat of wine after fermentation and aging. The same while brewing beer at a brewery is known as ...

''), leading to a distinctive yeasty aroma and taste. The lees may be stirred (french: bâtonnage) for uptake of their flavour. The lees are an important component in the making of '' ripasso'', where the leftover lees from Amarone are used to impart more flavour and colour to partially aged Valpolicella. Fujian red wine chicken is made from rice wine lees.

''Sur lie''

''Sur lie'' literally translates from

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

as 'on lees'. ''Sur lie'' wines are bottled directly from the lees without racking (a process for filtering the wine). In the case of great Chardonnay, such as Montrachet, this adds a toasty, nutty "hazelnut" quality and additional depth and complexity. Chemically, this can alter the oak flavour molecules, increasing the integration, and making the oak seem less obtrusive to the palate. This is desirable because oak tannins are polyphenolic acids, and can be harsh. This process can also give an added freshness and creaminess to the wine, and improve

color Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associ ...

and clarity. Muscadet is made in this fashion. The effect of the lees during bottle fermentation for at least 18 months on Champagne is considerable. The "bready" toasty notes associated with some of the greatest sparkling wines made are the result of ''sur lie'' aging.

Other uses

Beer on an element of lees (residual sediment) is also sold, such as many * Trappist beers * Unibroue Quebec, Canada-based ales/beers * Real ales of older styles (not India Pale Ale) Kombucha can also be brewed ''sur lie''.

Light lees protocol

In a process in which yeast is added to wine that has completed primary fermentation, this secondary yeast addition typically remains in the wine from 2–8 weeks, depending on the winemaker's goals. The yeast is stirred (''bâtonage'') frequently, and racked when the protocol is complete. Also known as secondary autolysis, a light lees protocol releases additional mannoproteins and polysaccharides that can influence the flavour, tannins, and acidity of the wine.

References

{{Reflist Fermentation in food processing Winemaking Yeasts it:Feccia (enologia)