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 A value-added tax (VAT), known in some countries as a goods and services tax (GST), is a type of tax that is assessed incrementally. It is levied on the price of a product or service at each stage of production, distribution, or sale to the en ...

wine Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are m ...

after fermentation and aging. 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 Trub is one of the largest municipalities of Switzerland (62 km²) in size, but not in population. It is located in the Emmental region of the canton of Bern in the administrative district of Emmental. History Trub is first mentioned in ...

– 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, ...

. Normally, the wine is transferred to another container (racking), leaving this sediment behind. Some wines (notably Chardonnay, Champagne (wine), Champagne, and Muscadet) are sometimes aged for a time on the lees (a process known as ''sur lie''), 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 language, French 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 tannin (wine), tannins are polyphenolic acids, and can be harsh. This process can also give an added freshness and creaminess to the wine, and improve Wine color, color 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, 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 Autolysis (wine), 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)