Substance growing on surface of wine

[Landwaster]

Hi -- pressed a batch of Nero Davola grapes 5 days ago. I was planning on racking after a day or two and adding malolactic bacteria, but I had to go out of town. I came back last night and discovered this stuff growing on the surface of the wine in both carboys. It doesn't seem to resemble the photos I've seen of mycoderma or Acetobacter. I racked both carboys, trying to avoid sucking up any of this gunk, and gave them a dose of sulfite. Any ideas what this stuff is?


https://flic.kr/p/zPz1b4

 

[Bartman]

Either those are just bubbles and you are worrying about nothing (unlikely, unless you have turned your account over to a noob ), or you're going to need to get a better image of it, perhaps from the side. We need some perspective/relative size to understand or recognize what you are seeing.

 

[Landwaster]

Should have explained the photo... you're looking down the neck of a 5g carboy, so the circumference is maybe 3inches across. There's some sort of film covering the surface of the wine with these specks about the size of a grain of sand. I didn't touch it so I'm not sure of its consistency, but it floated on the surface as I pushed it aside with a spoon and tried to scoop the stuff out.

 

[sdelli]

I would no worry.... This is residue from your press. Rack one more time.

 

[ibglowin]

I don't know that looks pretty nasty to me. If it's only been 5 days since pressing that is hardly anytime for bad stuff to grow in unless you started with something with a serious problem. If you sulfited it your going to have a hard time getting MLF to go.

 

[skipdonohue]

I would no worry.... This is residue from your press. Rack one more time.

ummm, I would totally worry, this looks like mycoderma, treat accordingly

 

[ibglowin]

I was thinking the same thing only its unusual to see it appear so fast. Heavy dose of sulfite is the cure and then keep the levels up to keep it at bay.

 

[stickman]

Check the consistency, if it feels like sand, it is most likely tartrate crystals. In certain circumstances they can float initially before sinking.

 

[grapeman]

Check the consistency, if it feels like sand, it is most likely tartrate crystals. In certain circumstances they can float initially before sinking.

That is true, but unlikely to form after just 5 days.

 

[stickman]

I agree, not the general rule, but tartrates can form very quickly depending on the must potassium content, tartrate is much less soluble in alcoholic solutions, so under the right conditions a portion of it can precipitate immediately after sugar fermentation and float to the top on co2. I have seen this happen in one of my wines right after fermentation, actually during the pressing operation, and was also alarmed until I looked closer.

 

[Landwaster]

Interesting...I do agree that 5 days is pretty quick for an infection to grow like that. And the fact that it was in both carboys is odd unless the must was infected. The stuff did look dry and like I said almost like grains of sand, so perhaps tartrate crystals are the culprit. The temperature dropped last week so our cellar went from around 69 when we pressed down to 62 when I got back from my trip, and I understand that colder temps help tartrate precipitate out of wine. In any case, I already racked and sulfited so I'll be monitoring these two carboys closely.

 

[sdelli]

Lol.... The sky is falling the sky is falling!