Help! Mould!

[Hibbs13]

I’m hoping for some advise. I am brewing an elderflower sparkling wine and it’s been fermenting no problem for 6 months with a couple of rackings. But now mould has appeared. It doesn’t taste gone off but I tried racking into a new sterilised demijohn and added a campden tablet but it’s come back again. I have a couple of questions:

1. Is there anyway to save the batch and kill the mould? (Even if it means it has to stay as wine rather than sparkling wine).

2. If I add more campden tablets will it kill off any future yeast I put in when I come to try and carbonate it in champagne bottles?

Cheers,
Paul

 

[Jayjay1976]

I've seen that in long ferments before, I think they are just yeast colonies growing on the glass. Don't worry unless it spreads and actually becomes fuzzy/filamentous. I had yeast grow across the surface of an imperial stout, freaked me out because it looked like mold but then over the course of a week it slowly sank into the beer and all returned to normal. Another batch of lower gravity stout started looking just like yours when it was about a month into secondary. Turned out to just be the yeast floccing out.

 

[jgmillr1]

I would try to remove the floating objects and then hammer the wine with campden tablets (say 1.5-2 tablets / gallon). By the time you dose it with more yeast at bottling, the free sulfite level should sufficiently low to not impede refermentation.

The larger issue is the large amount of headspace in the carboy. Oxygen in the headspace will feed mold spores. If you have a smaller carboy to tack into, that is the best solution. Alternatively, you could purge out oxygen from the air using a nitrogen or CO2 tank.

 

[Hibbs13]

Thanks both, I hope it was just yeast related but from a bit of reading I’ve been doing I couldn’t take the chance. I’ve added just under 2 campden tablets and topped up with wine so there’s only a couple of centimetres below the bung. I’ll leave it for a while to see what happens before I consider bottling.

 

[RPh_Guy]

FYI mold is allergenic and can produce toxins and carcinogens. It's obviously best to try to prevent it.
I personally wouldn't keep a batch with mold growth in it.

Adequate sulfite levels throughout aging combined with headspace minimization both prevent mold.