# Stirring Lees?



## skiboarder72 (Mar 13, 2010)

Alright I've read that after fermenting dry (after it's been racked over into the carboy and fermentation stops) that it is sometimes a good idea to stir the lees at the bottom and then wait for a few more days for it to settle before racking over into a fresh carboy and degassing and sulfiting. 

Does anyone do this? I remember hearing somewhere that it can help improve flavors.


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## AlFulchino (Mar 13, 2010)

stylistic choice... i dont do it on any of my reds...but i am getting into whites and will likely do this...someone can correct me here....but chardonnay which i have never made is often stirred ( the lees ) to give it that buttery quality....


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## Green Mountains (Mar 13, 2010)

I've not done this apart from when WE kits say to do it to initiate clarifying.

We're making reds only now so unless somebody gives a compelling reason to do it with reds we'll probably stick to not doing it. We're bound to make a white here soon though (we like to gift wine and not everybody is a red lover like us) and would love to know if this is a good practice for whites.


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## Dhorton (Mar 13, 2010)

I recall reading a thread about this on this forum and if I recall correctly it helps out with the mouth feel of the wine?...


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## AlFulchino (Mar 13, 2010)

http://www.brsquared.org/wine/Articles/surlie/surlie.htm

Sur lie and bâtonnage
(lees contact and stirring)
©Copyright Ben Rotter 2001-2009
www.brsquared.org/wine

"Sur lie" is the French term for leaving the wine in contact with its lees and "bâtonnage" the term for stirring this lees back up into the wine.

Why use lees?
When yeast cells die their cell walls breakdown, gradually releasing such compounds into the wine as polysaccharides (e.g. glucose), amino acids (and peptides), fatty acids, and mannoproteins. The compounds released can influence the structural integration of the wine in terms of phenols (including tannins), body, aroma, oxidative buffering and wine stability.

At the end of alcoholic fermentation, yeast cells autolyse. Yeast autolysis is a slow process involving hydrolytic enzymes which act to release cytoplasmic (peptides, fatty acids, nucleotides, amino acids) and cell wall (mannoproteins) compounds into the wine.

The primary reasons for sur lie ageing are usually based on stylistic goals: to enhance the structure and mouthfeel of a wine, give it extra body (an impact of polysaccharides on astringency), and increase the aromatic complexity, flavour/aroma depth and length. Lees also absorb oxygen, assisting in maintaining a slow and controlled oxidation during maturation. Lees stirring can increase the release of yeast compounds into the wine bulk. Stirring can result in a creamy, viscous mouth feel, and can enhance flavour complexity.

Some of the compounds from broken down yeast cells also contribute to wine in the following ways:
# polysaccharides contribute a roundness and volume to the palate
# mannoproteins can bind with anthocyanins and tannins to increase colour stability and decrease astringency
# the nutrients released from the dead yeast cells assist the growth of malolactic bacteria
# increased palate length, attributed to the late release of particular volatile compounds in the polysaccharide network of the fruit and yeast
# they can assist in protection from oxidation of particular fruit aroma compounds.
# the process of proteolysis, whereby proteins are hydrolysed to amino acids (which can act as flavour precursors, possibly enhancing flavour complexity) and peptides (which travel through the yeast cell walls causing an increase in nitrogen content).
# dead yeast liberate esters, particularly fatty acids with sweet/spicy (fruity) aromas (such as ethyl hexanoate and ethyl octanoate); this coincides with the time when fermentation esters (such as isoamyle acetate and hexyle acetate) experience hydrolysis, resulting in combined sweet/spicy/fruit aromas
# the release of amino acids and nucleic acids can enhance flavours and complex aromas, particularly at the end of the palate
# they yield a sweetness when binding with wood phenols and organic acids
# they modify wine esters and wood aromas
# they provide a natural fining, reducing more yellow colours in whites
# they improve protein stability (current research suggests that lees do this by producing an extra mannoprotein (polysaccharidic molecules which constitute ~35% of the yeast's cell) which prevents polymerisation of tannins, pigments and volatiles; and more of this compound is released when the temperature is increased, and with greater contact time and lees stirring frequency)
# they can assist potassium bitartrate stability, since mannoproteins act as potassium bitartrate crystal inhibitors
# they can reduce colour: the more yeast cell surface area, the higher the absorption and subsequent loss of colour.....................


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## djrockinsteve (Mar 14, 2010)

Al, How much lees are we talking about? A fine amount that appears after the main clearing or leaving the majority of the lees in the carboy to stir and when and how often?


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## Wade E (Mar 14, 2010)

Im not sure if this is called Surlies or not. I know Surlies is the act of keeping the fine less (sediment after racking off primary fermentation) and aging on them but I believe the act of stirring them all up is called "Battonage" and is typically only done with the Chardonnays like Al said to give it a Buttery taste and better mouthfeel. MLF on non kit wines can do this to an extent nut with a kit this is the only option to get this taste.


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## AlFulchino (Mar 14, 2010)

DJ...i dont like leaving any wine on gross lees after primary, ...having said that..i rarely rack a second time...preferring to wait until bottling time....however if a wine took a real long time to end secondary ferment then i would consider racking after that point.

i do like leaving my fine lees ...as you can see by the article above there are some good reasons to do it...the main bad one for me is possible loss of some color thru absorption to the dead yeast cells but if you are on fine lees then i dont think this is a real threat

if you ever have a big enough batch then the real way to test things is to use different carboys for example....on one you remove all the lees...the 2nd you leave light lees and do not stir, the 3rd you leave light lees and stir and so on until your lees are pretty heavy and then note the difference....and that may lead you to a stylistic decision.....


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## winemaker_3352 (Mar 14, 2010)

I have never left my wine sitting on the lees for a long time. I will rack it every 4-5 weeks if needed. I have read articles that long exposure to the lees can give your wine off flavors. Plus - racking this way also helps to degass it. Wrong, right, or indifferent - that's just what I do.


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## djrockinsteve (Mar 14, 2010)

Several of my aged wines will have a very slight amount of lees on the bottom when I bottle. I rack a second time around 6 weeks so most sediment has fallen out. I thought it was fine not to worry about that small amount. Just wanted to make sure.

I do have a fine covering in my Chardonnay. I'll have to give it a stir sometime and see. Thanks


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## AlFulchino (Mar 14, 2010)

you will always have some lees in the first two years...you cannot really avoid it...thats why a young wine gets filtered if it will be bottled early as much as anything.....the longer you let it sit as Tom always says he does ( i believe) then everything settles out and no filtering needs to be done...except for that polish that some require

i think the worst off flavors come from the dead yeast cells and by products...and that is why i rack off the gross lees.....i have never had an issue w fine lees

if you want good color then frequent punch downs will give you all that you need and all that a particular grape var. can offer .....


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