Off-note (sulfur?) in apple wine

[Awest89]

I'm looking for any suggestions for an apple wine that's got an off, unpleasant note to it. It may be sulfur? It's not strong enough to knock you over by the smell, but it's distinctly unpleasant. I've let the wine sit for an hour and it improves some, but does not go away. I remember seeing somewhere that off-gassing could be an option to try to save it, but am not sure how I'd go about that.

For reference, apples were pressed last October, standard campden/yeast/fermentation process used, and after racking twice it's been aging in the carboy ever since. It had the off smell the last time we racked it, and we hoped it would go away but it obviously has not.

Thanks for your help!

 

[winemaker81]

Is the smell rotten eggs?

 

[BernardSmith]

A smell of rotten eggs is caused by hydrogen sulfide, and H2S is caused by stress to yeast. You might try whipping the wine to see if introducing oxygen can solve the problem (a lack of O2 is often the cause). There are other solutions but you DO want to get rid of the H2S because hydrogen sulfide can become fixed in the wine as what are called mercaptans and it is almost impossible to remove that compound.

 

[Rice_Guy]

* what yeast? some yeast will have a high nutrient demand and at fast growth/ high temp canabalize themselves producing sulfur smells
* what nutrient regime?
* as Bernard says you don’t want mercaptans, on ten month wine the sulfur may have reacted
* I try to be a reductive wine maker which increases the risk of sulfur smell, ,,, on a tannic red grape you should get away with oxygenation but apple doesn’t have the reserve polyphenols to soak up the oxygen, ,,,, I would sample a jar half full and shake instead of the whole carboy, ,,, seems you have some of the answer by letting it stand in a glass for an hour.
* any tannins? ,,, I use crab apple for tannin