The first thing to do would be to confirm how much bacteria actually are in the wine. Microscope observation can provide information on potential spoilage micro-organism that would explain the slow growth of bacteria.

  • If the bacteria cell count is low or inexistent, a step in the bacteria preparation and addition may have been mishandled, or the medium is too tough. Another inoculation with potentially a stronger strain should be considered. A detoxification of the wine with yeast hulls could also help before the re-inoculation as other micro-organisms (yeasts in particular towards the end of fermentation) could have produced stress-related toxins in a difficult environment (see below).
  • If the bacteria cell count is higher, at a level of population close to or high enough to trigger the fermentation (around 106 cell/mL), bacteria may be missing something. Simple steps can be taken at this point: homogenization will keep bacteria well dispersed in contact of their substrate malic acid (also keeping the sampling accurate) and a slight aeration can help trigger the fermentation (not oxygenation!). A few degrees in temperature can play a significant role as well in this enzymatic based fermentation, and warming the wine a little bit will certainly accelerate the process.



Bacteria may also just lack nutrition. As shown in the graph, there was a high population in this wine, not converting malic acid, and adding a specific bacterial nutrition helped; the malo-lactic fermentation started a few days after the addition and was completed in less than two weeks.




Recent works highlighted the specific needs of bacteria in terms of nutrition: 5 amino acids (AA), 2 vitamins and 2 mineral co-factors play a particularly important role in the malo-lactic conversion metabolism.
The LAFFORT ML nutrient MALOSTART® has been recently revisited to have a higher concentration in these vitamins and AA, while minimizing the concentration in AA precursors of biogenic amines.
The other component of this product is a yeast hull that has been selected for its adsorption of short and medium chain fatty acids (C6, C8 and C10) that are toxic to bacterial growth and activity. MALOSTART® hence provides a detoxification of the wine and lowers that stress on the bacteria.



MALOSTART® is a complete and precise nutrition for your malo-lactic fermentation. Along with the other factors described above, it might save you days of heating the wine or even from a second inoculation!


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