Mold on Wine?

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Nov 29, 2016
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Making wine from grape juice for first time. Had six gallons of Barolo for six weeks (went through primary in pail for roughly one week and placed into Carboy for the last five weeks. Removed Airlock the other day and placed natural cork stopper to begin the aging. Yesterday noticed a small kind of white cotton like swirl on top of the wine and two or three tiny little (what I'm assuming are fruit flies) though they are white in color. Is this likely mold? What can be done from here?
If you can send a picture it would help. This sounds like it could be excess protein, which looks scary and nasty, but will rack off. Unless you get better advice, I recommend that you rack the wine being careful to take the wine from the bottom and let the cottony stuff float down on top of the wine and then leave it in the old carboy. Add 1/4 tsp kmeta and move on. It may come back but it should be less and then another racking should remove it all, if it's protein. I've not done straight juice before but I have seen something like this a couple times in the kit's I've done. Nasty looking stuff, but harmless. At least I hope that's all it is for you. And of course remove the flies the best you can. Good luck.
what you have is flower of wine, a surface bacteria that grows with air. I would follow the racking instructions above, and double dose the k-meta. double check your ph and make sure it is in range. double check airlock also.
Put the airlock back on. Most folks leave airlocks on for a year at least, or use the airless silcone locks. If I'm reading you right that wine is only about 6 weeks old. You will blow a gasket with a solid cork.

Pam in cinti
Thanks for the tips! I hope you are right. I was nervous to rack because didn't want to expose to too much air but I will try this and see if it goes away.
I will put the Airlock back on as well. I took off because it seemed like the positive pressure on the Carboy was gone (the water in the s-type lock leveled back out).
THese are the best I could do for photos. I know they're not easy to make out. In the second photo you can see what I was referring to and tiny fruit fly next to it



Hard to tell what it is, but as was mentioned above the remedy is the same either way. One additional piece of advice, add more wine to get the level up to the bottom of the neck of the carboy. If it is flower of wine this will help starve it of oxygen, and if it isn't you need to do it anyway to help prevent oxidation as it ages. I think you'll be fine with racking, Kmeta, and topping up. Keeping the airlock is good at this point too as it may continue to degas for a while. The fluid backing that you mention could result from a change in the weather. Did you have a high or low pressure front move through about the same time? Atmospheric pressure will do that.
So far I see what could be undissolved Kmeta and maybe a speck of yeast floating on top. It still could be protein, or flowers of wine. Luckily the same treatment basically for both. For flowers of wine, which needs air to live, rack to clean carboy leaving top layer behind if you really think flowers is the problem. double dose the kmeta, dissovling in warm water before you put it in to make sure that what you are seeing isn't undisolved kmeta. Also, either rack into a smaller carboy or find a way to top up your wine. That headspace is too big for long term storage. Flowers of wine would thrive with that much air. Also not good becaue of long term oxidation.

Once I thought I had flowers of wine. When I reracked I put the wine almost touching the bottom of the bung. My reading said that would kill any remaining flower due to lack of oxygen. My wine came out great. But my problem could well have been Potassium sorbate that hadn't dissolved well also. that stuff is hard to dissolve and looks so suspicious it has made me jump thru hoops many times.

Pam in cinti
Sorry to step on your toes, Ted. It takes me a long time to post, and you had already said basically the same thing. At least we agree!

Pam in cinti
Sorry to step on your toes, Ted. It takes me a long time to post, and you had already said basically the same thing. At least we agree!

Pam in cinti

No problem at all, agreement posts tend to give us all confidence. Much better to have consensus or at least polite discourse than what I've seen on another thread I've been following the last day or two :)


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