Malolactic fermentation is a process of fermentation where tart malic acid is converted to softer-tasting lactic acid. In its strictest sense, fermentation (formerly called zymnosis) is the energy-yielding anaerobic metabolic breakdown of a nutrient molecule, such as glucose, without net oxidation. ... Malic acid is a tart-tasting organic acid that plays a role in many sour or tart foods. ... Lactic acid (α-hydroxypropionic acid) is a chemical compound that plays a role in several biochemical processes. ...

It is accomplished by lactic acid bacteria, which consume malic acid to produce energy. Depending on the bacteria present, it can occur naturally, but in commercial winemaking, malolactic fermentation typically is initiated by an inoculation of desireable bacteria. This prevents undesireable bacterial strains from producing off-flavors. Conversely, commercial winemakers actively prevent malolactic fermentation when it is not desired, to prevent accidential initiation. Species L. acidophilus L. bulgaricus L. plantarum L.reuteri etc. ...

Because it consumes the malic acid, all of which is present at the time the grapes are crushed, malolactic fermentation can take place at any time during or after alcoholic fermentation. A wine undergoing malolactic fermentation will be cloudy due to the presence of bacteria, and have an uncanny smell of buttered popcorn, due to the production of diacetyl. Species Vitis acerifolia Vitis aestivalis Vitis amurensis Vitis arizonica Vitis x bourquina Vitis californica Vitis x champinii Vitis cinerea Vitis x doaniana Vitis girdiana Vitis labrusca Vitis x labruscana Vitis monticola Vitis mustangensis Vitis x novae-angliae Vitis palmata Vitis riparia Vitis rotundifolia Vitis rupestris Vitis shuttleworthii Vitis tiliifolia Vitis... Balls of butter on a plate Butter is a dairy product made by churning fresh cream. ... Popped kernels Popcorn or popping corn is a type of maize which puffs up when it is heated in oil or by dry heat. ... Diacetyl is a natural by-product of secondary or malolactic fermentation. ...

In winemaking malolactic fermentation is generally encouraged in many red wines and some white wines, particularly those that are aged in oak. Unoaked white wines, such as German wines generally do not undergo malolactic fermentation. Malolactic fermentation tends to create a rounder, fuller mouthfeel in subject wines. Malic acid tastes slightly of apples and this can be tasted in the wine, while lactic acid is richer and more buttery. A glass of red wine Wine display at the Mt Markey Winery This article is about the beverage. ... This article is about the beverage. ... German wine from Franken in the characteristic round bottles Many people think of Germany as a beer producing country, and the beers of Bavaria in particular are known very well internationally. ... For other uses, see Apple (disambiguation). ... Balls of butter on a plate Butter is a dairy product made by churning fresh cream. ...

Sometimes malolactic fermentation 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 secondary fermentation should not be confused with benign carbonation, known as spritz. Spritz or spriz (from German Sprizen, to squirt or spray) is a name for Scandinavian cookies which are made by forcing the dough through a cookie press. ...