MLF and when to inoculate

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Oct 15, 2021
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Morning All!

I've been doing some research and reading some posts and threads regarding MLF and when to inoculate. There is alot of information out on the world wide web so I'm turning to you guys to pick your brains and see what you guys do when it comes to MLF and when you inoculate.

I'm currently making some wine from fresh juice pails. I called over to the supplier where I bought the pails from and they advised me that no adjustments were made to the juice. Currently, I have the wine in their carboys, alcohol fermentation is complete, there is a nice layer of Lee's at the bottom of each carboy. The other night I racked off one of the carboys, cleaned it, sanitized it and transferred the wine back to it. Added 1/4 tsp of K-Meta and Degassed. My plan was to do the same with the remaining carboys but I started reading about MLF and the beneift of it.

My question to everyone is, did I miss the window to inoculate? I've read that some inoculate soon as alcohol fermentation is done. It's been almost 3 weeks since I pitched the yeast.

Looking forward to your responses!!

Aug 5, 2011
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O'Fallon, MO - Just NorthWest of St. Louis, MO
There's two major schools of thought as to when to inocculate, school 1 soon after alcohol fermentation begins or at least before it finishes and then school 2 is after it finishes. Probably most folks here lean to the school 1 idea, I personally am a school 2. I lean to school 2, since I use my fermentation buckets for things I would not want to have MLF happening, so I finish AF, press, into carboys to let settle for 1-3 days and remove the gross lees. Then add my MLB. Either is probably fine, just go by what you prefer. Waiting 3 weeks probably isn't to long, however, the adding of KMeta prior to inoculation with MLB may be a problem. The bacteria used for MLF are very susceptible to the amount of SO2 which has been added, the manufacturers give a range of as low as 12 ppm causes problems to some allow there to be up to 50 ppm of SO2 (combination of free and bound SO2, contributes to that number). So, in the carboy you have already added KMeta you may have issues getting it to start.

If you choose not to even do MLF, which is a valid choice also, you may want to consider adding lysozome to inhibit it from happening by itself. I think if you hae never had malolactic bacteria in your winemaking area, the odds of it happening spontaneously are very low, but it is possible. My first few attempts with juice buckets and from grapes, I did not induce malolactic fermentation. Those wines might have been a bit sharper than ones where I have now introduced the bacteria, but might not be.

Other factors which contribute to MLF not happening are ABV above 14-15%, PH being below 3.2 or being excessively high.
Feb 25, 2017
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Centerville, Northern Virginia
I'm a school 2 person as well for no reason except it's how I started and it works for me. You obviously are too late for school 1. Craig brought up some very good points, most importantly don't add K-meta to your second batch. Also don't use a liquid MLB, they are the ones that require very low SO2. Use VP 41 or one of the CHs that do tolerate a higher SO2. The 3 weeks is not a problem either, I wait until all my wines are pressed and racked off the gross lees before I introduce the MLB and it's always around three weeks from the first batch. You may also want to consider a way of testing the progress.

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