Malolactic fermentation
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225991420
2008-07-16T10:27:02Z
Gderbysh
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'''Malolactic conversion''' is a process of a change in wine where tart [[malic acid]] is converted to softer-tasting [[lactic acid]].
It is accomplished by [[lactic acid bacteria]] (such as ''Oenococcus oeni''), which consume malic acid to produce energy. This can occur naturally. However, in commercial [[wine making]], malolactic conversion typically is initiated by an [[inoculation]] of desirable bacteria. This prevents undesirable bacterial strains from producing off-flavors. Conversely, commercial winemakers actively prevent malolactic conversion when it is not desired, to prevent accidental initiation and maintain a tarter, more acidic profile in the finished wine.
Because it consumes the malic acid, all of which is present at the time the [[grape]]s are crushed, malolactic conversion can take place at any time during or after [[alcoholic fermentation]]. A [[wine]] undergoing malolactic conversion will be cloudy due to the presence of bacteria, and may have the curious smell of [[butter]]ed [[popcorn]], due to the production of [[diacetyl]].
In winemaking, malolactic conversion is generally encouraged in many red wines and some white wines, particularly those that are aged in oak. A prominent example of this is the prevalence of malolactic fermentation in [[California]] [[chardonnay]]s [http://lamorindawinesociety.com/wineschool/glossary/index.html]. [[Unoaked]] white wines, such as [[German wine]]s, generally do not undergo malolactic conversion, which tends to create a rounder, fuller [[mouthfeel]]. It has been said that Malic acid tastes slightly of [[apples]], and this can be tasted in the wine, whereas lactic acid is richer, even unctuous, and more buttery tasting.
Sometimes malolactic conversion can occur unintentionally after the wine is bottled. This is almost always a fault, and the result is a slightly carbonated wine that typically tastes bad. The carbonation from this type of change should not be confused with benign carbonation, known as [[Spritz (wine)|spritz]].
==External links==
*Purdue University - "[https://www.foodsci.purdue.edu/research/labs/enology/Malolactic%20Fermentation.pdf The Joy of Malolactic Fermentation]" Accessed Dec. 27th, 2007
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[[Category:Oenology]]
[[ca: Fermentació malolàctica]]
[[de:Malolaktische Gärung]]
[[es:Fermentación maloláctica]]
[[et:Malolaktiline kääritamine]]
[[fi:Malolaktinen käyminen]]
[[fr:Fermentation malolactique]]
[[nl:Malolactische gisting]]