Sunday, April 08, 2007

Starting Malolactic Fermentation

I started malolactic fermentation this weekend on the 2006 grapes with the following process: I mixed up about 40 grams of Acti-ML in about 16 oz of 2006 "kitchen sink blend". To this I added the contents of a 2.5 gram package of Enoferm Beta freeze-dried bacteria. After a 30-minute rest at room temperature, this mixture was added to the carboys in the cellar. The current cellar temperature is 50 degrees F, moving slowly upward. The malolactic bacteria are not supposed to be very active below about 57 degrees F, so it may be awhile before any malolactic fermentation begins. We'll see...


  1. I'm going to start malolactic fermentation this weekend on my 2006 grapes (several year kit wine maker, first year grape wine maker). I tried a few months ago and it didn't take. I found out later my SO2 was too high. I'm trying again using Lalvin VP41, a more tolerant bacteria. Do you have any tips for a first timer?


  2. Dave,
    My new move this year was to add the Acti-ML nutrient. I won't be able to say if it helped for a month or two though. Watch temperature too.

  3. Hi, Regarding MLF, one other parameter to watch in addition to Free SO2 level and temperature, is pH. It's really tough to get MLF going below pH 3.4. By the way, how do you monitor your MLF to mank sure it has begun, and to know when it has completed?

  4. RC, I have to admit, I depend on time more than any test to confirm MLF. By keeping innoculated wine in carboys through the spring and summer as the basement temperature warms, and then not bottling til the next vintage of grapes arrive in the fall and winter, I have had no problem with post-bottling fizz. So, I'm only hypothesizing that this is a suggestion my MLF is completed.

  5. Hello again,
    It's been a long time between comments. I should be more prompt. I represent a company the produces and sells Quick Tests for wine analysis. There are tests available for L-Lactic Acid to tell if your MLF is actually underway, and also for Malic Acid, to tell when MLF is completed without having to guess when the bubbles stopped, and so you don't leave your wine unprotected needlessly. The tests don't require equipment, take only 4 minutes, and are sensitive to 30 mg/L. This may sound like a commercial, but they really work, and are used by commercial and by amateur winemakers. There's more information at, or you can email me directly with any questions.

    Thanks, Reluctant Chemist.