Rotten Egg Smell during fermentation

I have a 28.5 brix, 5g/l TA syrah. no sulfites added at crush. have not made any adjustments, but was about to add back some water. fermentation has started to kick in after a 3-4 days cold soak. innoculated with D80.

today noticed a rotten egg aroma as I was starting the two a day punch downs.

another tank with the same pick is not experiencing the issue

any thoughts on what this is? Should i increase punchdowns to increase oxygen?

Try adding a little DAP and swirl around the must to blow off the existing sulfides just to make sure the yeast in that fermenter aren’t nutrient deficient. It could also be temperature extremes. What temp is the fermentation? Are the two fermentations the same temp?

Bin ferms never get as much O2 as tanks in which you are doing pump overs. That’s also why they tend to get a little more sluggish than tanks. Yeast likes oxygen.
A little bit of a stinky ferment isn’t usually anything to freak out about, but they can turn “bad” disulfide-wise, so I would just try to get a bit more oxygen into them. If you have a small pump and wand with a screen on it, you can do quick in-bin pump overs. It is also good for the sluggish ones.

Berry - thank you. added in some DAP. the start of fermentation has been a little sluggish, i thought it might be temperature related. but seems like it could also be nutrient related. D80 has a moderate/medium nitrogen requirement.

Linda - awesome, thanks. I’ll step up the punchdowns and really try to get as much O2 in as I can. It is in a small 300L stainless tank. I don’t have a way to do pump overs, no valve at the bottom of the tank. I might just use a bucket to scoop the must out and add it back in. any other ideas for aeration would be awesome!

also, thanks for your help with my question on the chardonnay, you were right as always!

Hey Tim,

The smell of Hydrogen Sulfide (rotten eggs) is associated with reduction. This is commonplace in grapes containing low nitrogen levels as well as in fermentations that are lacking oxygen (small containers, barrels, etc). The yeast produce off odors because of the low nutrients in the juice. It’s very important to jump into action when you smell this because once you get to lower brix levels (~8 and below), there isn’t much room for correction.

Ideally you’ll first add some yeast nutrients to help them out before following up with DAP. Aeration, such as pumping over, rack and return or even punchdowns (taking into considerations you’re small open top tank) can help aerate the juice and help fermentation. If none of this works, or if you catch it too late, you’ll have to use some copper to reduce/remove the smell.

For a pumpover, or rack and return, you could siphon out juice into buckets or a food grade container and then siphon (or pour) it back into the tank you’re using. That should give you the desired effect of Delestage or a pumpover.

Best of luck.

Tommy Pace

The easiest way to aerate a liquid is to use a sparge pipe (a tube with fine holes drilled in the end) connected to a lubricant free, clean compressed air supply.

Make sure you start off with very low air pressure.

Take a barrel wand and hook up a compressed air pump. Stick the wand in the must; turn on the pump and let about 5 minutes of air bubble through the must. Clean as a whistle.
Whether in bin or barrel, it works for me.
Best, Jim

Tim - Tommy’s advice sounds like it will be the most practical for the situation I suspect you’re dealing with, ie. no compressed air, pump, etc. to work with. Developing H2S during fermentation is not unusual and as Tommy noted, it’s much easier to deal with it now rather than later. Another tip is that you don’t want to add nutrients once the fermentation gets to lower brix - they can work against you by providing food for brett and other things you don’t want in your finished wine.

D80 almost always gets stinky. I would have suggested something different for a high brix ferment. You’re going to need to be all over nutrients. Don’t overdue it on the DAP. Plan on delestage 1 per day until it’s below 8 brix or so. O2 sparge sounds fun, too. Settle this after press before barreling down. The lees on this one will be an issue.

If you’re not going to water back, you might need to consider a bayanus strain like UV 43 in order to get this to finish.

Hey all - thanks so much for the help. I’m a little stressed since this is syrah from Monte Rosso! I did water back a little, went 1/2 way on the targeted water addition to go from 28 to 25 brix.

I added the recommended DAP yesterday. still smelling some H2S this morning, so added a little more, but much improved to almost neutral. This tank was at 15 brix last night, so sounds like I am catching this just in time. I will try my own version of destelage today, which will be bucketing the must out of the 300L and 200L tanks, into food grade plastic fermenters, then back in. I had wanted to use D254, but my buddy (who I am doing this project with) suggested D80 (and D21 in another tank that got H2S this morning).

Should I add in yeast nutrients at this stage, or is it getting too late?

Sounds like I need to assume the lees will be a problem. How often should I rack to prevent issues? Should I keep in the stainless tank until malo is finished?

Should I finish the water addition at this point, or would that create more issues?

Syrah, in my experience, seems tend toward stinkiness anyway, no matter what you do.
Do not add nutrient below 10-12 Brix.
I personally would do ML in tank due to the fact that you will have more thermal mass in a tank rather than barrel, and it will be more likely to finish faster that way. If you are worried about finishing (which might be an issue if you didn’t water back enough), I would go ahead and pitch my bacteria when you are lower than ~7 Brix but before dryness so that you can get it in there before the alcohol is finished producing, and while your must is still warm.
Water at this point? I personally wouldn’t unless I thought I had really undershot my initial water add. You said you did half the water add. Did you start fermenting right after, or did you let it cold soak some more? If you started fermenting immediately, there may have been more sugar soaking up that you did not notice due to the fact that the yeast were already getting started. In which case, you may never know what your true starting Brix were. Just be watchful for signs of sluggishness toward the end.
As far as D80 is concerned, it has been a good strong finisher in my experience. We had a tank of Zin go dry with D80 and ended up at just over 18% alcohol. We did super aerated pump-overs, though.

Did you measure yeast assimilable nitrogen, ammonia, or alpha-amino compounds? If you have a starting number you can target the add a little better. If your just low on YAN dap works but you may need to add something like fermaid k or similar product for a more complete nutrient. I think they recommend adding at 1/3 sugar depletion.

With just half the water add at .6 conversion your looking at 15.9% etoh, with the water add your looking at 15%. I don’t see the water creating any more h2s issues, it will dilute sugar, acid, and nutrients. I guess you could aerate the water a lot before the add to try and get some more dissolved o2 into the ferment.

I wanted to thank everyone here who contributed to this thread. I am thankful for your help and expertise. I’m happy to report back that all is well with the Syrah. The sulfides are gone and the tanks are down to 2.2 and 1.7 brix.

I plan to follow Ian’s advice to press to a tank, settle for 24-48 hrs, then rack off to a stainless tank. I think I’m going to leave the wine in the stainless until malo is done, then barrel down.

Tim,

It sounds like you got a lot of good input and took care of the H2s issue. Nice. Power of the Board.

Be careful with the racking after press unless you are able to test for dryness, at least with a clinitest pill. If you rack if off the lees before it is dry, a stuck ferm is more than possible, particularly at what I’d guess are pretty high ABV #s.

Good luck with finishing the wine!

Tim - In general I settle for 24-48 hours and on occasion longer. I’ve never left something in tank through Malo on purpose though. I feel better about being in barrel with a fermentation bung to release gas than a tank, especially a variable top. No science behind that, just how I feel. I also like that if Malo is slow I can haul a barrel outside in the sun in January and finish it off.

FYI for next year- you may know this, but when you water back, its a very good idea to saignee as well. Winebusiness.com has a fantastic article about some trials that were done. We also always like the saignee trial better than water only.

Another fun thing is to ferment concurrently on D80/D21 together. We have gotten some amazing results with multi yeast ferments.

Thank you Andrew. Yes, if I ever have a glimmer of success at any point, I will certainly have the people here to be thankful for and be in debt to. I waited until the wine went to negative brix, then pressed. Let settle after pressing for about 72 hours then racked off the gross lees

Makes sense , thank you Paul. Sounds like you don’t see any issues with being in a tank, just more of a comfort level issue with barreling down. I will probably barrel 1/2 and leave half in tank. Only have one 30gal barrel and 75 gallons on wine.

I did not know this, really interesting. Off now to search for that article. Seems counter intuitive to add water, then bleed off some juice.

On the the multi yeast ferment, I think I ended up doing this by accident. Inoculated my barrel fermented Chardonnay and saw a longer than anticipated lag in both barrels. So inoculated with a different yeast.

I’m actually a little scared of the d21 and D80, but having said that ended up with same issue on a Grenache inoculated with rc212. In the viticulture class I am taking at uc Davis, there was a comment about low nitrogen this year and more people needing to add DAP than in the recent past. Not sure if this is true or not, but my issues could have just been due to low nitrogen vineyards.

It’s saignee first, then add water. Just adding water would lessen the skin to juice ratio, so the point is to lower the alc. without making a more dilute wine.

I have heard of people who add water first, then saignee. I’ve never done it that way personally. Then sometimes you have cheap owners who just want you to add water.

Linda, what would be the reason for doing it that way? To lower sugar before bleeding off juice to make a Rosé‎ or would there be some other reason? I don’t think I’ve heard of anyone doing that.