Mark,
I agree with Ed. It is not likely that even at 25ppm SO2 you would stop
MLF. Give it a bit of time, and if you dont have any results consider a bit
of ML Nutrient and raising the temp.
John Dixon
"Mark Willstatter" > wrote in message
om...
> (Brad B.) wrote in message
. com>...
> > Here's my situation: I have a small (about 10 gal.) batch of Merlot
> > that has finished sugar fermentation and has been pressed and racked
> > off the gross lees. There is still some lees in the bottom of the
> > carboys. I inoculated with MLF culture (Chr. Hansen) and warmed up
> > the wine to about 70 deg.F. So far, after about 4 days there is no
> > activity and I suspect it is due to the SO2 I added at crush (about 50
> > ppm). I initially added this amount due to some rot in the grapes I
> > had, and completely forgot about the MLF I would need later.
> >
> > In any case, I checked free SO2 with a titret and I get about 35 ppm
> > (which seems high following fermentation but I know those things
> > aren't the most accurate). So, what should I do now? Did the high
> > SO2 kill the ML culture or will they spring to life once the free SO2
> > levels decrease to their liking? I am thinking about racking,
> > stirring, and adding some ML food, but I am mostly curious about the
> > effect this has on the culture and if I will need to add another
> > culture later.
> >
> > Thanks in advance...
>
> It would be very unusual for enough of your 50 ppm to remain after
> primary fermentation to bother MLF. Also, titrets are well known to
> overstate SO2 on the order of 30 ppm - so your test verifies that your
> free SO2 is probably near zero. MLF likes having the lees around and
> being anaerobic, prefers a high CO2 environment - neither of which
> will be helped by racking. It also sometimes takes awhile to get
> going - keep in mind that this is a process that can often take some
> time to get started and weeks (or even a couple months) to complete.
> Your temperature is fine and your MLF bacteria should have the
> nutrients they need in what you have already. My advice at this point
> would be to hang tight and be patient. Also, if you haven't done this
> before, keep in mind that MLF activity is pretty subtle compared to
> primary fermentation. When it's going strong, you can usually detect
> tiny CO2 "comets" (assuming you're in glass), especially up at the
> neck but it's usually not enough to make an airlock go wild. If you
> don't see anything like that within a week or so, then maybe you can
> start worrying! I hope that helps.
>
> - Mark W.