Is sulfur normal?

[worlddivides]

I mentioned this in a thread about something completely different for my previous mead, but it was never definitively addressed.

So, my current orange blossom mead has been fermenting since Monday. I added the first nutrient addition and DAP immediately after fermentation started and there was basically no smell for the first two days (other than a regular sweet honey smell), but at the end of the second day since adding the nutrient, a sulfur smell started and got stronger and stronger. Since I had read that sulfur was a sign that the yeast were stressed and that it usually meant that they had run out of nutrients, I added the rest of the Fermaid K and DAP before going to sleep. Within an hour of that, the sulfur smell disappeared. The next morning there was no sulfur smell either, but around noon the sulfur smell came back but not as strong as it had been. I can't believe that the yeast has ALREADY consumed all of the Fermaid K and DAP. And I've already used up all of the nutrient for this batch, so I'm not sure if this sulfur smell is normal or not. Last night it was a very strong sulfur smell, which went away with the nutrient additions, and now it's a weak sulfur smell. Like rotten eggs.

I've heard that high fermentation temperatures can cause this too, but I know that can't be the case. The optimal fermentation temps for my yeast are 70 to 75F, and I have been keeping the yeast between 66F and 72F with it mostly around 70F most of the time.

If it's normal, I can learn not to worry. But if it isn't normal, I'm open to any suggestions.

The airlock has been bubbling like crazy since fermentation started, so I would expect that the majority of the sugars have already been consumed by now, but I don't know how much sugar is left and I've never taken a gravity sample during an active fermentation before (I usually wait until the fermentation is at least 95-99% done).

Thanks in advance for any helpful advice and info you can provide!

 

[valverij]

While some SO2 is produced during fermentation, I wouldn't worry about it this early. You'll experience all number of weird smells and flavors in primary.

 

[loveofrose]

Sulfur smells usually indicate that there is not enough Nitrogen (DAP). How much did you add and what yeast are you using?

 

[worlddivides]

Sulfur smells usually indicate that there is not enough Nitrogen (DAP). How much did you add and what yeast are you using?

I'm using White Labs WLP720 (sweet mead - which is a slightly less attenuative version of the WLP715). I put in 15 grams of DAP, the first 7.5 grams immediately after the fermentation started and the other 7.5 grams about 2 days later (about 1-2 hours after the sulfur smell first started).

At the moment, there is still some sulfur smell, but it is very mild.

 

[loveofrose]

I've been told the yeast is a nutrient hog. If it gets more than just a bit stinky, add more DAP. Fermaid O would be better since you don't know the gravity.

 

[worlddivides]

I've been told the yeast is a nutrient hog. If it gets more than just a bit stinky, add more DAP. Fermaid O would be better since you don't know the gravity.

Thanks for the info. I just had a whiff of the fermenter. The inside of my fermentation bag has a moderate sulfuric smell, but the smell right around the airlock doesn't smell like sulfur at all.

Before I pitched the yeast, the gravity was 1.082, but without checking the gravity again, I really have no idea how much it's dropped. I am using a Speidel, so I could use the spigot to get out a sample, but I don't know if that would be a good idea during an active fermentation (since I've never done that before).

I don't have any more DAP or Fermaid in my house... Well, technically I have some DAP, but it's in a pretty big package of yeast nutrient (composed mostly of food grade urea and diammonium phosphate) that I've used for fruit-based wines. I could use that if it would help.