White Labs WLP675 Malolactic Bacteria I

White Labs WLP675 Malolactic Bacteria I. Malolactic Fermentation is the conversion of malic acid to lactic acid by bacteria from the lactic acid bacteria family. Lactic acid is less acidic than malic acid, which in turn decreases acidity and helps to soften and/or round out some of the flavors in wine.

These liquid cultures are available in vials to inoculate 6 gallons or 1 liter sizes to inoculate 60 gallons.

Please note: We recommend caution with using WLP675 with wine kits, which contain potassium sorbate and effect the viability of malolactic bacteria.

General Instructions

• Wait for fermentation to reach a gravity of approximately 5 Brix, towards the end of fermentation.
• Warm culture to room temperature and inoculate must. If one inoculates at the beginning of fermentation, the yeast and WLP675 could compete for resources and may cause a stuck fermentation.
• To determine the completion of the MLF (malolactic fermentation), monitor the depletion of malic acid. The accepted value for a completed MLF is around 30ppm.

Inoculations larger than 59 gallons

To inoculate larger volumes, we recommend inoculating with a larger culture. If time is not an issue, one can propagate the bacteria to larger volumes, but keep in mind that malolactic bacteria is a slow-growing, fastidious organism. Depending on the size of the propagation, it could take weeks to grow.

Propagation Instructions

White Labs recommends allowing 7 days for tenfold growth. The best media for propagation is apple or grape juice (or must, if available), supplemented with fructose, malic acid, and nutrients such as that contained in MRS broth.

Approximately 2% of the total volume of media can be composed of finished wine, in order to acclimate the bacteria to alcoholic conditions.

We recommend an incubation temperature of 30˚C.

Optimal pH The optimal pH is approximately 4.0, but WLP675 will handle a pH of 3.3 in red wines and 3.1 in white.

Additional Information

WLP675 has a high tolerance to low pH (3.0), low temperature environments (down to 55˚F or 12˚C), and high alcohol percentages (up to 15% alcohol by volume).

SO2 The SO2 tolerance = 10ppm