Darn It! My Wine Smells Like Rotten Eggs

Homemade WineFor the first time ever I ordered juice concentrate, your merlot and blackberry, to try making a large batch of my favorite flavors. Well, I followed the directions to the letter and it all fermented nicely in the primary. After 5 days racked it to the secondary, 6 gallon glass carboy but for the first time left a little head space of a couple inches figuring that it would be ok since it it was still bubbling a little. It has been two weeks and I racked it again to get it off the sediment and OMG it smells of sulfur, or rotten eggs! Once the wine was in my plastic bucket the smell dissipated and the wine tasted ok but today I checked it and there is still a smell. What did I do wrong? I’ve heard of adding egg white to try to take away the smell…. what can I do? I really hope I don’t have to dump it. HELP!

Name: JoAnn S.
State: WI
Hello JoAnn,

All fermentations put off some sulfur or rotten egg smells. Some much more than others. When a wine smells like rotten eggs, what you are actually smelling is hydrogen sulfide. There are many of reasons why one fermentation might produce more hydrogen sulfite than others, but here are the big four:

  1. Fermenting With Wild Yeast: Shop Wine Yeast
    In your case, we can rule this out because you are using a wine ingredient kit that comes with a domesticated wine yeast. But if you were relying on wild yeast to do your bidding, this would most likely be the reason why your wine smells like rotten eggs. Some wild yeast can produce tremendous amounts of hydrogen sulfide.
  1. Lack Of Nutrients:
    Not having enough nutrients in the fermentation is another cause of high hydrogen sulfide output. But again, you are using a wine ingredient kit that has been nutritionally balanced. The yeast nutrient is at its ideal level in the wine concentrate, so we can also rule this out for your particular situation.
  1. Fermenting At Too Warm Of Temperature:
    Fermenting your wine too warm is another common reason for a fermentation to produce and abundance of hydrogen sulfide. Temperatures that are above 75°F. are suspect, and anything over 80°F. are likely to be problematic to some degree.
  1. Overworked Yeast: Shop Yeast Nutrients
    This happens when there is too little wine yeast to do too much job. There have been many times when a winemaker will accidentally kill a significant portion of the wine yeast when rehydrating it in warm water. If the wine yeast is put in rehydrating water that is too hot, or the yeast is left in the water for too long, more yeast cells will be killed than anticipated by the wine yeast producer. This sets the stage for a fermentation with too little yeast, and in turn, produces too much hydrogen sulfide.

The Overall Theme:
It is important to point out that all the above reasons relate to allowing the yeast to ferment under stress. When a wine smells like rotten eggs, start look at thing that might be putting fermentation in a stressful situation.

Having a wild yeast that is fermenting out of its normal element is stressful; having any yeast ferment with a shortage of nutrients, or ferment in a temperature range that is uncomfortable to it is stressful; and having a little bit of wine yeastShop Potassium Bisulfite doing a lot of work are all stressful things that will lead to high hydrogen sulfide production. Having said this, the whole idea is to keep the wine yeast happy and you will keep the hydrogen sulfide production down.

What To Do Now:

— Give It Time: A lot of the hydrogen sulfide will release and dissipate on its own. It sounds like this may be the case with your wine currently. And, more will dissipate when you bottle the wine.

— Add Sufites: Also, adding a dose of sulfite to the wine will help to drive out the hydrogen sulfide. You can add the sulfite in the form of Campden tablets, sodium metabisulfite or potassium metabisulfite. Just following the directions that are on the package and let the wine sit for a few days.

— Use Copper: If the wine still smells like rotten eggs, you can pour the wine through a copper scouring pad. When the wine comes into contact with copper a reaction will occur the encourages the hydrogen sulfide to release as fumes. The reaction will cause the copper to corrode, so your may need to use more than on copper pad.

Happy Winemaking,
Ed Kraus

Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.

13 thoughts on “Darn It! My Wine Smells Like Rotten Eggs

  1. At what point do I add brandy to my Cabernet Sauvignon, before clearing and degassing or just before bottling?

    Thank you for your help

    • Laney, you will want to add the brandy to your wine after the fermentation is complete and the wine has cleared.

  2. Ed, if too little yeast is added, can one add more yeast later on in the fermentation?


  3. Hello JoAnn,
    I had the rotten eggs or burnt rubber H2S problem with a white wine some years ago. I did all the things suggested by Ed Kraus: rack the wine a couple of times to let it air out; added more sulfites and last but not least: I added a miniscule amount of Coppercarbonate, which I had read in a book. All these measures combined resulted in a wine that had no more rotten egg smell altogether. Just be patient. Good luck

  4. Too little yeast? But if there are enough yeast nutrient, why doesnt the yeast just multiply until there is enough?

    • Rene, what you are adding to the wine is not an amount of yeast so much as you are adding a starting colony of yeast. The yeast in the packet represents the minimum number of yeast cells recommend to start an active fermentation, regardless of batch size. When adding a packet of yeast to 5 or 6 gallons of wine, the yeast will typically multiply to around 100 to 150 times what you start with.

  5. You mentioned one cause as being the yeast being left too long in the rehydration water. What are the guidelines for rehydrating yeast?

    • Ken, the typical hydration directions for dry yeast state to dissolve the dried yeast in 2 ounces of warm water (100° – 105° F.). Let stand for 15 minutes without stirring. After 15 minutes stir and add to must.

  6. I have a question about adding brandy to a port-style dessert wine from a kit.

    Fermentation has finished and I have 3 gallons currently clearing. The materials indicate that this kit should produce a wine of about 15% ABV. I’d like to increase the percentage to about 18% before bottling. If I add brandy for that, do I need to make any adjustments, e.g. acidity?


  7. Ed,
    I have a homemade blackberry wine that has had the rotten egg smell since the first racking on Sept 26,2020. Since then I’ve tried racking it aggressively 3 separate times and the 3rd time I tried the copper and it still has the egg smell. Is it just a lost cause?

    • Well, it could be a lost cause, but my guess is that repeating the copper treatment will eventually get the wine to come around. Treating the wine with sulfites between treatments will also help to drive this odor out.

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