Simple Mlf Process Familiar To Anyone?

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Hi, I sure was glad to find this forum!
I am a two year winemaker and curious about this process. I have been advised I can simply MLF by adding the cultures to my primary fermentation process, as primary fermenting winds down with no regard required to Ph. Once added, I am told to continue punching until the cap falls and then press and continue as had in past. Unfortunately, I find no reference to this method anywhere!!
Can anyone let me know if I am doomed here, now that I have already introduced the cultures?
Bob, you are not doomed. I have read that you can start MLF either during primary or when the primary is complete. If adding during primary you want to add it when the fermenation is nearly complete. This gives the ML culture some of the nutrients that are still present during the primary fermentation. To start MLF the must temperature needs to be between 73-77 degrees, which it probably is during primary fermentation. Another advantage is that assuming MLF completes before or soon after fermentation, this allows SO2 (which provides security against bacterial and oxidative attack) to be added to the wine sooner rather than later. The down side is the risk of volatile acid.

The advantage to starting MLF after primary fermentation is that you get to control when you do it. Let's say you are making the wine where you cannot control the temperature (e.g. a garage) and you live in a colder climate. You can start the MLF in the Spring when the temp gets to within the optimal range.

You should be fine with starting the MLF with your primary fermentation.
Thanks for the input. My only concern now is temp. Since the cold should only slow down or prevent fermentation from occurring, if I warm up the room I should be able to get the process going. Is that a correct assumption?

I appreciate the help as the wine had a great early taste, smell and look, so I hate to loose it!!!
Bob, what is the temp of the must now? Here is some information on MLF dug up regarding temperature. I was off slight in my initial temp for the optimal temp.


MLF will proceed faster at higher temperatures. When no SO2 is present in the wine the optimum temperature range for MLF is 23-25°C (73-77°F). (Maximum malic acid degradation will occur at 20-25°C (68-77°F) [Ribéreau-Gayon et al., 1975].) However, this decreases with increasing concentrations of SO2 causing 20°C (68°F) to be more suitable. The following table indicates MLF speed at given temperatures.

Delay Temperature
slowed by months / essentially no malic acid decarboxylation
10°C (50°F)
slowed by weeks 12-13°C (54-55°F)
begins to slow 15°C (59°F)
optimum 20-25°C (68-77°F)
MLB death >30°C (> 86°F)

Most strains of Oenococcus oeni either cease to grow or grow very slowly below 15°C (59°F). However, cells remain viable at low temperatures. [Jackson, 1994].