Malolactic Fermentation-Theoretical Advances and Practical Considerations

There are two main fermentations associated with the vinification process. Alcoholic fermentation (AF), which is conducted by yeasts and malolactic fermentation (MLF), which takes place as a result of the metabolic activity of lactic acid bacteria (LAB) of the genera Oenococcus, former-Lactobacillus, Pediococcus and Leuconostoc. MLF is defined as the biotransformation of L-malic acid to L-lactic acid and carbon dioxide and in addition to deacidification, contributes significantly to microbial stability and often to the improvement of the sensory profile of wines. Therefore, the abiotic and biotic factors that affect MLF, along with its correlation with quality characteristics, has been in the epicenter of intensive research. In addition, practical issues that accompany MLF have also been considered and adequately assessed. The aim of the present review was to explore and critically discuss MLF from both theoretical and practical perspectives.