There’s A Sulfur Smell In My Wine!

Wine With A Sulfur SmellI’m making a Sauvignon Blanc from a 6 gallon bucket of refrigerated fresh juice that was inoculated with a wine yeast by the producer. Instructions on bucket: bring must to 76 degrees stir 2x daily, recover with bucket lid and rack to secondary fermenter at 1.020. My starting SG 1.090 and I racked last night after two weeks to secondary at 1.020 and noticed the must smells like a hard boiled egg. Any suggestions, or will this smell work its way out during future rackings?

Name: Michael N.
State: Pennsylvania
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Hello Michael,

So sorry you are having such an issue with this batch.

The hard-boiled egg smell you are referring to is obviously a sulfur odor. This sulfur smell in your homemade wine comes from hydrogen sulfide.

Hydrogen sulfide is a compound that is naturally produced during a wine fermentation. All wine fermentations will produce some hydrogen sulfide, however there are some scenarios that can cause more of it to be produced than others. Apparently, your wine falls into one or more of these situations:

 

  • It could be that your wine is fermenting with a wild yeast strain. Some wild yeast are not that good at fermenting a wine must. They have to work harder causing an over-production of hydrogen sulfide. However, if the wine must was sulfited before your received it, this situation is not very likely. Wild yeast are very sensitive to sulfites. They would have easily been destroyed by it.
  • A nutrient deficient wine must can cause a sulfur smell in a fermenting wine. Whether the yeast is wild or domesticated, it will have to work harder to get the job done when they are malnourished, again, causing excessive hydrogen sulfide production. Your wine must does not fit this scenario very well. If you are using 100% grape juice, there is a significant amount of nutrients available. Only on a rare occasion will a grape juice fermentation produce an abundance of sulfur odor because of a lack of nutrients.Shop Yeast Nutrients
  • Having a fermentation that is too warm can cause a sulfur smell in fermenting wine. If the fermentation was over 80°F., this can put the wine yeast under additional strain and increase the likelihood of too much hydrogen sulfide being produced.
  • Having too little yeast trying to do too much work can cause a sulfur smell in a fermenting wine. If for some reason the wine yeast added did not have enough viable cells (old yeast), or if some of the wine yeast was destroyed during storage or shipping of the wine must, this can cause an over-production of hydrogen sulfide.
  • Using a domesticated wine yeast that naturally has a higher likelihood of producing hydrogen sulfide could be why you have a sulfur smell in your fermenting wine. Not all wine yeast are the same. Each one has it’s own unique set of qualities. Some wine yeast have a higher propensity towards producing higher levels of hydrogen sulfide. These wine yeast are more sensitive to the above situations.

 

Finally, it could be any combination of the above. Quite often things are not so cut-and-dry in wine making. It could be an orchestration of two or three of the above situations coming together to put your wine in the mess it is currently in.

The good news is that almost all of the time this particular fault in a wine is correctable. Quite often, time is all that is needed. Doing a racking after the fermentation can significantly help to release the sulfur odor. So does adding sulfites such as: Campden tablets, potassium  metabisulfite and sodium metabisulfite. Any of these will help to drive the hydrogen sulfide out of the wine.

Shop Potassium BisulfiteMichael, my suggestion to you is to do nothing right now. In fact there is nothing that you can do at this stage that would help the situation. Continue on as you normally would with any wine. When you get the wine to a point that it is ready to bottle, that is when an evaluation needs to be done. Simply smell and make a determination: is there still a sulfur smell in the wine? If so, there are additional steps that can be taken.

 

Removing Sulfur Smell In Wine

Most of the time the sulfur smell of hydrogen sulfide will go away with normal rackings of the wine. The addition of Campden tablets or potassium metabisulfite as normally prescribed in a wine recipe will help to drive out the sulfur smell, as well. So, it is very likely that the sulfur-y smell will go away in due time.

But, there are times when racking the wine is not enough. In these situations, removing the sulfur smell from the wine may require you to treat the wine in a splashing manner. Let the wine run down the side-wall of the fermenter as it comes out of the siphon hose when racking. Or, you can try pouring the wine from one open fermenter to the next. In many instances I’ve seen this work successfully.

Be sure to treat the wine with potassium metabisulfite after doing this to drive the oxygen out of the wine, reducing the risk of oxidation, in your wine and, as mentioned before, it will help to drive out some of the hydrogen sulfide.

In almost all cases, removing the sulfur smell from the wine will be accomplished with the above treatments, but there are some rare instances when the above treatments just are not enough. In these more drastic situations you will want to treat the wine with copper. Yes, I said copper! When the wine comes into contact with copper, a reaction will occur that causes the hydrogen sulfide to release more freely, removing the sulfur smell from the wine.

Shop Wine KitsThe easiest way I have found to do this is to purchase copper brillo pads. Place a brillo pad in a funnel and pour the wine through it. You will notice that the brillo pad will start to corrode very quickly. This is from the reaction we are seeking. If the brillo pad starts to look spent, then feel free to put another one in its place. Again, you will want to treat the wine with potassium metabisulfite after performing the treatment to drive out oxygen that was introduced into the wine.

Michael, I am confident that removing the sulfur smell from your wine will be no problem at all for you. Be patient. Do your rackings and potassium metabisulfite additions as you normally would. When it comes time to bottle the wine, if still have a sulfur smell in the wine, then you can consider treating the wine with splashing, and so forth, but I would not do anything before then.

Happy Winemaking,
Ed Kraus
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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.

25 thoughts on “There’s A Sulfur Smell In My Wine!

  1. Ironically I just racked a concord wine yesterday where one batch was ok and the other had a sulfur smell and I new in the past you had an article about the same thing and I was going as the same question today LOL

  2. Hello Ed, first of all I look forward to the “Winemaking@eckraus.com” emails every couple of days. A source of great advice which I have used many times. Thank you.

    This article about the sulfur smell describes something I have experienced several times with my late season Apple wines which I was able to reduce as you described, by splashing back and forth between open mouth containers.

    One item though that I don’t understand, how would, as you mentioned, adding the sulfur-based products Campden tabs or potassium metabisulfite reduce the hydrogen sulfide and the sulfur-y smell. I had thought when I had that problem it may have been from the initial inoculation of Campden tablets prior to adding my yeast. Was I wrong?

  3. About 5 years ago I made 15 gallons of Merlot from fresh grapes and freaked out when I opened the airlocks to do my first racking: It was a very, very strong smell of rotten eggs and I thought I’d have to throw it away. I did some quick research, including emailing Kraus, to see if I could revive this wine, which I thought would be dead. Multiple rackings, beating it with a degasser, and finally the copper trick. My copper trick was splicing a piece of drinking-water copper tubing in the plastic hose between the pump and bottling cane. I did this each time I racked and eventually the smell went away and it was one of the best wines I ever made. I named it Lazarus.

  4. Thanks, I will try using copper brillo pads. Question: Should I wash and sanitize the copper pads before using them?
    thanks

  5. Hi. First thanks for this great website and information it gives. Believe or not I have also come across the problem of hydrogen sulfide in my still fermenting wine. This is my first time ever wine from a fresh fruit – in this instance – blackberries & raspberries. I made a 5 gallon batch based on 31lbs of bramble. As per recipe I added 5 campden tablets to my crushed berries (topped up with water) and then next day added 5tsp of pectolise and 5tsp of yeast nutrient and Lalvin RC212 yeast. I stirred the must once every day for 7 days and then filtered it through nylon bag in order to remove the pulp. In 7 days SG has dropped from 1.095 to 1.030 fermenting at around 22C. I always sanitize everything I work with so I doubt that anti sanitary conditions could have caused it but next day (today) after I filtered my “yet to be wine” I have noticed it has stopped fermenting (or so it seems) and it smells of hydrogen sulfide. I did what’s suggested i.e. – pouring from one container to another and it has reduced the smell. I have no means of measuring the amount of sulfites at the moment. My question is (being worried that my fermentation might be stuck which I will check tomorrow by taking another SG reading) do I need to do something about it i.e. – try to introduce more yeast or add more yeast nutrient? Thank you.

    Regards,
    Janis Freibergs
    Southampton, UK

    • Janis, thank you for the kinds words. I wouldn’t do anything until you verify with your hydrometer that you do in fact have a stuck fermentation. If you find that it is stuck, I would take a look at the article posted below on the most common causes of fermentation failure to determine the cause. Before you can correct the situation, you need to find out what is the cause.

      Top Reasons For Fermentation Failure
      http://www.eckraus.com/wine-making-failure

  6. the production of excess hydrogen sulfide could have been caused by warming the must too fast,
    also, I always ferment my white wines at 58 degrees with a yeast that will ferment at that temp
    such as lalvin ec1118,the lower temperature retains the delicate flavours and nose.
    this is the temp the professional winemakers that I know use.

    regards ,
    Norm Fulstow
    Baddaginnie. Australia

  7. foul smelling wine ,,,,all alacante grape,,,,,,,been doing the same procedure for years ,,,,,this is my first problem I ever had,,,,,having your campden tablets mailed to my house,,,also will try the copper pad remedy,,,,,,i will return with comments after use your methods,,,,,thank you ,,,,,,,,GREG from Brooklyn NY

    • Hey..first year I did all Alicante grapes as well..changed the yeast I used this year (always did my fathers way using champagne yeast) to a Lalvin RC 212…first time with this yeast and first time I have ever smelled this after making wine 20+ years with my father. And we always use sodium/potassium metabisulfites to clean, sterilize, etc.
      Got grapes direct from California like I always do..this year they appeared little black mold on the Muscat’s.
      I added 1 tab of sodium metabisulfite to each carboy at first rack. Will update at second racking.

  8. Hi, will the copper brillo pads create copper sulfate? Should we fine or filter the wine afterwards, to remove copper sulfate. I read that CS is poisonous.

    Thanks, Len

    • Len, when using the Brillo pad method, the copper corrodes and the only sulfate it releases is what is needed to release the sulfur. No more no less, so it is not contaminating your wine. Wineries will add copper sulfate in small doses. When it reacts with the sulfur it neutralizes it. We do not sell copper sulfate because it can be too easily abused by adding too much. You are correct, copper sulfate can be poisonous. Sulfur reacts with the copper and is much safer because the wine reacts as a gas that dissipates so it is not going in the wine.

      • It actually forms copper sulfide, which is harmless and appears like black crystals or fine sand. That will settle out and then you’ll lose it in subsequent rankings. I just treated a Montepulciano that went sideways using pre-1982 pennies, which were 95% copper. You could also use copper pipe, or the copper ground stripped out if some Romex cable. Clean and disinfect everything of course. Pennies worked like a charm.

  9. Hi. I have a strong rotten egg smell in a brew I put down as a rose. The smell became apparent a couple of days after starting. Should I pour it all out into buckets now, then back into the fermentor or wait until the ferment is mostly complete? The smell stinks out the shed. I have never experienced this before. There is about 25 to 30 litres of a mix of merlot, cab franc and malbec from the vineyard I manage in Hawke’s Bay New Zealand, and I am reluctant to throw it out just yet.
    Cheers,
    Jeremy Smith.

    • Jeremy, if it is time to rack the wine, go ahead. If it is not time to rack, then I would wait. You should not need to throw the wine out. As the article states, almost all of the time this particular fault in a wine is correctable. Quite often, time is all that is needed. Doing a racking after the fermentation can significantly help to release the sulfur odor. So does adding sulfites such as: Campden tablets, potassium metabisulfite and sodium metabisulfite. Any of these will help to drive the hydrogen sulfide out of the wine.

      • I am making a batch of tart cherries/pomegranate wine and it now has a sulfur foul smell. To drive hydrogen sulfide sulfur smell out of wine how much potassium metabisifite or campden tablets should I add?
        Should I vigorously stir after adding to carbon? Thanks for any advice you can offer.

  10. I love this blog, thanks so much for the wonderful info! Am making strawberry wine and I made the mistake of not crushing camden tablet when I added to must. I stirred a few times in next 24 hrs hours, then added other ingredients and strained and transferred to sanitized vessel w airlock. First day went well but I noticed a white ring at top of liquid. I worried it may be the tablet and I took off lid and stirred it all. I left airlock off for that evening and covered with paper towels and rubber band. Next morning I put airlock back on and now I have a strong sulfur/vinegar smell. It’s been bubbling like crazy all day, but did I mess up by stirring it and now yeast is under too much stress? Should I just keep as is and rack down the road? Thanks 😀

    • Dana, no you did not do anything wrong by stirring juice. As a matter of fact, when making wine with fresh fruit, you should be stirring the wine daily while the fruit is still in the fermenter to prevent a hard cap from forming. Did you take at the man other reasons listed in the article that can produce a sulfur order. If you think it is a vinegar odor, please take a look at the article below to find out what could be happening.

      My Wine Smells Like Vinegar
      https://blog.eckraus.com/wine-smells-like-vinegar

  11. Thanks Ed, last year I had a very gassy wine and I ran my wine through copper Brillo pads and this trick worked perfect.
    As I siphoned my wine from one carboy to the next carboy I placed a Brillo pads in the funnel and splash the wine crossed Brillo pads by slowly shaking the siphon hose over the brillo pads. I repeated this twice and the sulfur smell is gone.

  12. Hi,
    I used a wine kit for 30L but decided to make 8L in two 5L bottles. I kept the 5L water bottles in a fermentation barrel wrapped in blankets. I had a temperature sensor in the barrel that tells me the temperature. The heat was added using hot water bottles.
    I think I used the correct amount of yeast, however the yeast nutrient was mixed with the yeast and so perhaps not enough went in.
    The must started stinking of rotten eggs – I read many articles including this one, but not before I tasted it and spat it out. I had to vomit vigorously.
    I decided that the wine is toxic after reading about hydrogen sulfide, but I added a stabilizer containing sulfites, a finings liquid containing sodium meta bisulphate, malic acid, and crustaceans, and silicon solution.
    I shook the bottle and released a lot of gas. I then decided (after vomiting) that I would never drink this, so I added some solid core copper wire to the bottle. The other wine must is still fermenting.
    I am expecting the copper wire will corrode if the stabilizer, finings and racking (shaking in this case) doesn’t remove the hydrogen sulphide. The other bottle might be salvageable, but the instructions say to taste the wine for dryness.
    Is the rotten egg smell completely avoidable? Is wine normally racked to remove sulphur? This all seems very dangerous and toxic.

    • Dave, While we cannot guarantee that it will never happen, if you look at the reasons that cause this to happen and avoid those reasons, the chances are greatly reduced.

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