rotten egg smell?

i have 6gals. of cab. from grapes. after 1st rack i have an egg smell. is the wine bad or is there a way to save it.

Maybe I will buy some small bungs and use wine bottles full to top up when I don't have a gallon.

try buying a couple of 1liter wide mouth sodas, then use the bottles when your finished drinking the soda. a # 6 and # 7 bung will fit. dont forget to clean bottles before use. they work in a pinch. i dont know how long you can keep wine in them tho.

Saran wrap with TWO rubber bands (in case one break) will not only keep the air (and bacteria) out, but it will also act as an airlock, and allow any
CO2 to escape (the pressurized gas can push past the rubber bands). So you don't need to order smaller bungs.

I assume you removed the mold from the surface before racking? It might not be a bad idea (even now) to pour the wine through a coffee filter, although the sulfite should kill it. The additional aeration should also help somewhat with the H2S problem (if it is H2S).

H2S is the chemical formula for hydrogen sulphide, which is the chemical which gives rotten eggs their peculiar odour. The smell is quite different from permanent wave (?) solutions, but it is more likely that you are smelling H2S. If so, racking, aerating, and stirring with a piece of copper wire, or length of copper pipe, will help. I believe the most common cause of H2S problems is over-sulfiting.

The mold is a different problem, and almost certainly the result of the excess head room.

The wine still has a "perm solution" type smell which it has had from the start. As far as taste it is still pretty bitter but then so is all the wines we have so far. They seem to be getting better with age.
You suggested adding sulfite. I have a little Potassium Metabisulfiite and a lot of Sodium Metabisulfiite. Would either work? How much would I need to add to a 5 gallon carboy. I also have Campden Crush tablets and
Potassium Sorbate stabilizer.
I guess I should consider another way of toping off. The gallon jug was the smallest container I had at the time and it was not topped up. I hate to add water because most of our wines have such a weak flavor to begin with. Maybe I will buy some small bungs and use wine bottles full to top up when I don't have a gallon.

It looks as if the low alchol may have done in at least a gallon of my wine. I just went down to take a look. For the batch of watermelon/ elderberry I had a 5 gal carboy and a gallon carboy half full that I was going to use to top off when racking. The smell is getting better with age but the gallon has developed some mold on the top. I don't recon I have any choice but to trash it. The 5 gal carboy does not have any visible mold.
What I was considering doing was to rack it, and add enough sugar to bring it up to around 11%. My question is how do I know how much sugar to add.
Unfortunatly I do not have a starting brix reading.
Also, it had stopped fermenting quite a while ago. Will all the yeast be dead? Will I have to add some and if so how much?
I think that maybe the reason the 5 gal did not mold is because it is full. The lack of air may have prevented it from spoiling to this point.
Any suggestions are appreciated.
Thank you,
Tom and Shelley t

Give it time. What you are smelling could be the by-products of the yeast.
I do not remember a sulpher/egg smell with my cab, but there was a very noticable sulpher/egg smell when I did a lager beer last winter. What yeast are you using? I used a vial of the White Labs cab yeast.

I always add 1/4 tsp of Potassium Metabisulfiite or Sodium Metabisulfiite yo
5 gallons of wine. I use a little less than 1/2 of a 1/8th teaspoon for 1 gallon
I always use it whenever I rack and I have no problems with mold or even stopping the ferment in secondary
Potassium Sorbate is used to stop yeast from regenerating itself. I very seldom use it because I feed my wines with sugar to high alc to kill the yeast. I use Cote de Blanc yeast for wines I want less alc volume in.

I did not remove the mold from the top but I was very careful not to disturb it. When I got down to where the it would begin to syphon up the mold I stopped and dumped the rest. It mold was a very light haze on top with a few small spots. It was not covering the top of the wine.
I'm not sure what you are referring to when you say H2S? It has a smell that we orginally called "perm solution" but I think it could be a "rotten egg" smell. Either way it has gotten noticibly better with age and racking does seem to help.

8% is a little low and could give you a spoilage problem. 11 to 13% is the standard for commercial wines for that reason. I personally would add a little more sugar to get 11%
I purchased some copper sulfate which is for getting rid of sulphur odors after fermentation, but it has to be used just right. I bought it and I am afraid to use it.besides, the problem went away with a couple of rackings done in the same day

If, by "perm solution", you mean your wine smells like the chemicals used by beauty parlors to make hair curly (e.g. Ammonium hydroxide, Ammonium thioglycolate, Glyceryl monothioglycolate, and Sodium hydroxide ), I suggest you take it to the nearest toxic waste dump.

If you are describing a different odor, there may be a remedy.

Sulfite (SO2) should not be added to a fermenting wine. It can and should be added pre-ferment, and post-ferment to a level of ~50ppm depending on the condition of the wine. Potassium Metabisulphite is preferable to Sodium, but both will do the job. 0.33 gram per gallon will yield ~50ppm, as will one
CRUSHED campden tablet per gallon. Potassium sorbate has an entirely different purpose.

You can top off with distilled water or similar wine. Alternately, you can add sterilized glass or stainless steel marbles to the carboy. Alternately, you can use a variety of smaller containers. If you leave excess headroom (more than an inch), you are inviting (if not guaranteeing) bacterial spoilage.