Lee - If you have malic and lactic acid spots on your chromatography paper
you have a ML fermentation in process. In some of my wines that have a MLF
underway it's very difficult to see bubbles at first. The wines have just
been cloudy like you mention. As the temperature warms up and/or after the
bacteria have really increased in number ML fermentation is more apparent
with lots of bubbling.
>
> I'm open to suggestions. Lysozyme addition? Coarse filtration followed by
> sterile filtration? Re-chilling? Gelatin? All of the above?
>
I read here that sulfite will stop or prevent MLF. This may be so if the
sulfite is added before a MLF gets underway or if enough SO2 is added.
However, I've had MLF take place in some of my wines that I believed were
well protected with sulfite. Since I add ML culture to my red wines the
organisms are just floating around in my cellar and it's real hard to
prevent MLF in my white wines.

I had good success stopping MLF by adding Lysozyme at 200 to 500 ppm (at
least 0.75 grams per gallon) in cloudy wines that show malic and lactic acid
spots like you describe. The wines I've treated have become crystal clear
in a couple of days.

Once you get the MLF stopped and the wine clears your 0.2 micron Duofine
filter will render the wine sterile. But sterile operation is next to
impossible in typical basement operations. Everything downstream from the
filter has to be sterile...that's the big problem. But, proper SO2 levels,
K sorbate at 200 ppm and sterile filtration should be enough.

Check out PIWC, Scottlab or The Winelab for some info on Lysozyme. Good
luck.

Bill Frazier
Olathe, Kansas USA