Film on top of wine

[Flyman]

Not mead but still need some advice. Raising Champanel grapes and harvested my first crop. Got enough to make 5 gallons of wine plus a little jelly. Crushed the grapes and sulfited them. Waited 24 hrs and pitched the yeast (Lavlin EC-1118). Primary fermentation took about 10 days after which I removed the must and racked to a carboy. Great color and aroma but VERY acidic. PH is now 3.08 and acid titration is about 16. Malic acid test show malic greater than 500 mg/L.

So, to cure the above problems I added spring water to get the acid under 10 (this worked, as it is now about 9), and decided to do a malic fermentation to reduce the malic acid. When I added the water, I wound up with 8 gallons of wine (a 5 gallon and a 3 gallon carboy). I split the malic yeast between the two. Finally, here is the question.....The 5 gallon carboy has a film of something (bacteria, mold, ???) on top and the 3 gallon does not. Does malic fermentation cause this film or is the cause most likely a sanitation issue?

I need to rack and get the sedimentation (lees) out but thought I would tackle this problem at the same time. My thought was to rack and add meta if its a sanitation issue (5 tablets?) and add calcium carbonate if the acid is still high.

The current SG is about 1.009 (started at 1.090) and have seen no evidence of further fermentation (no bubbles in airlock). However, with the PH at 3.09, I feel like the fermentation could be stuck because of low PH.

Any advice would be appreciated as Mesquite Mead is next up on my list.

[Hambone]

Sorry I can't help ya with the tech questions, but let me know when it is ready and I will come help ya drink it.

[Flyman]

Done Deal for Derek:). You have to pick up:D

[Ben Brewcat]

Hmmm I can't remember if malolactic culture forms a pellicle, but does the film look like little stalactities? It might be the malolactic, and the fermenter volume or geometry is delaying one vessel. Sanitation is always a worry, but pellicles are not always evil but I don't know if it might be normal in this case. Check the documentation of your malolactic culture.

[Flyman]

I racked this morning and checked the Malic Acid. Looks like less than 150 so evidently the film was the malic fermentation (or at least the malic fermentation worked). Adjusted the PH to 3.5 and added a little oak. Time will tell. SG at this time is 1.10 so there is a little room for more fermentation, but I am also happy with where it's at. The film was mostly film but there were a few crystaline bumps that you could call stalatities. Did not look like moldy bumps.