There is an expectation in red wine making that the secondary fermentation, Malolactic Fermentation (MLF), will produce a clean taste, smooth mouthfeel and complex character in the wine. MLF results from the growth of bacteria in the wine. Not all bacteria are good. It is important to make sure that a certain strain of malolactic bacteria (MLB); namely, oenococcus oeni, is present and dominant. Other strains that can be present are leuconostoc oenos, pediococcus and lactobacillus which can produce unpleasant aromas and tastes such as mould, sauerkraut and/or a bitter aftertaste. These bad guys can come in on the grapes and/or reside in used barrels and equipment. Which MLB will grow faster and dominate the MLF depends on several factors: wine temperature, pH , yeast strains, nutrients … If the wild/uncultured strains are allowed to produce a spontaneous MLF, there can be an increased risk of spoilage organisms. Inoculating the wine with a cultured MLB insures the population growth level of that bacteria is sufficient to promote and sustain the MLF. The competition with yeast and other MLB for available wine nutrients could cause a MLF lag due to insufficient MLB nutrients in the wine and increase the risk of spoilage organisms. The requirement for nutrients by the MLB is the same as for the yeast in the primary fermentation. Yeast will consume much of the available nutrients (including added nutrients such as GoFerm and Fermaid K) during the primary fermentation. It has been shown that the bayanus strains of yeast (Prise de Mousse/EC1118 for one) are more apt to produce conditions inhibiting a complete and favorable MLF.

The addition of a MLB nutrient will provide a favorable environment when inoculating with a cultured MLB. I have inoculated with a cultured MLB for several years at home and at the winery (Witch Creek) with good results, but there still have been times of a lag in the growth phase of the cultured bacteria. The MLF did not complete before the onset of the colder winter temperature and the need to add SO2 to protect the wine. It usually did not finish until the following Spring when the temperature warmed up and the SO2 level was low. The presence of the various bacteria strains in the wine during this delayed MLF phase increased the chances of the "bad guys" (Leucono- Pedio- Lacto) to develop. This lag growth phase also encouraged the excessive growth of Brettanomyces resulting in additional unpleasant flavors.

LESSON LEARNED: THE QUICKER THE MLF COMPLETED, THE BETTER THE CONDITIONS ARE FOR A SAFE AND FLAVORFUL WINE.

The 2006 Harvest was my first experience of using the MLB Nutrient (Malostart) in the MLF phase. The results shown in the table below reveal that in 100% of the trials the MLF was COMPLETED IN LESS THAN ONE MONTH AND MANY IN ONLY TWO WEEKS. The early MLF completion allowed the full and early additions of SO2 and removal of the airlocks to better protect the wine in the maturation phase.

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