Help: Fermentation produces sulfur smell; alternative source of nitrogen?

My three day fermenting mead is still bubbling at the airlock faster than once a second, but it is starting to smell like sulfur. I understand that this is probably due to nitrogen deficiency, which should be alleviated by diammonium phosphate. However, I do not have any diammonium phosphate, and probably can't get it quickly enough either.

Am I correct in thinking its a nitrogen problem, and if so, are there any other solutions for my problem? Thanks in advance.

Oh, and I have access to an aerator and bee pollen, but no real yeast nutrient.

I can't think of anything other than yeast nutrient that will help. Sometimes meads with fruits aren't deficient, since the fruit provides nutrients but there aren't many nutrients in honey for the yeast.

well i brewed with apricot preserves and I mashed 2 lbs of malted barley. the sulfur smell is faint; could it be ok without any added nutrient? I'm thinking about adding some bee pollen, I don't think it could hurt, but I won't if it is possible that the sulfur smell will mellow out.

i woudld think the fruit and the mashed grain would give you enough nitrogen at least ot get a good ferment started. might wanna add DAP in small amounts after 2 weeks, but it should be ok at this point.

If you have no access to commercial nutrients, but you start to smell hydrogen sulfide in a fermenting mead, there are a couple of other things you can use depending on how far fermentation has already gone. Do you have specific gravity measurements at the start of, and during the course of, fermentation? Yeast produce sulfides for a number of reasons, but the most common is lack of assimilable nitrogen. One other cause can be stress brought on by temperature extremes, pH extremes, or fermenting in the presence of chemicals toxic to the yeast. Do you know for sure that your apricot preserves were "preservative free" or could they have contained any sulfites, sorbate or benzoate? Finally, different yeast strains differ widely in their nitrogen needs, and in the amount of sulfide that they'll throw if they are nitrogen starved. Which yeast strain did you use?

Back to that first, and most likely cause - the lack of sufficient nitrogen. While the malt and the fruit would help, if the primary fermentable in your must is honey you probably didn't bring along enough assimilable nitrogen from those other adjuncts, unless you added lots of the apricot preserves. If you already (after 3 days) smell H2S the problem is likely to get worse with time - not better - given the way that yeast metabolism works.

But don't panic - I have a quick and somewhat dirty trick that may work in your case! Simply take some baking yeast (the active dry yeast from Fleischmann's or Red Star that you can buy by the packet or small jar in most grocery stores will work) and turn it into a combination yeast nutrient/yeast hull treatment. Take 2 to 3 grams of active dry baking yeast per gallon of your must (so for 5 gallons of must use 10 to 15 grams of yeast), and drop that into about a cup of boiling water in a pot on your stove. Stir well to avoid the yeast clumping up and allow it to come back to a boil. Cover, shut off the heat and allow it to cool to room temperature. Then add this yeast slurry (stirring or swirling to get as much of the cooked yeast bits up into suspension as possible) to your must and stir it to distribute well.

The boiled yeast both provides some assimilable nitrogen (in the form of amino acids from the dead yeast) and provides yeast cell walls, otherwise known as yeast hulls, which can bind with yeast toxins and drag them out of solution as they percolate down to your lees layer.

This may help with your sulfide problem, and it is probably your best quick fix if you have no yeast nutrients around.

Thanks for the advice. There is a reasonable chance that the preserves might have had some preservatives in them; I'm going to check on that. My OG was 1.091 @ 72º; haven't measured since. I don't have any litmus paper, either. I did already add some "brewer's yeast" from walmart into a cup of boiling water, and then added that to the carboy, but according to your calculations I didn't add enough.

wayneb said:

But don't panic - I have a quick and somewhat dirty trick that may work in your case!

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I love dirty, but sometimes quick is not all it's cracked up to be.

Great post, lot's of information and hopefully it will help a lot of people.

I have heard of this smell being called "Rhino Farts" and that it is a completely normal part of creating mead, and that it handles itself and goes away. I am now confused.

Sulfur odors are not a natural part of mead making.

Sulfur odors, when left alone, may not go away. The H2S may form more complex molecules like mercaptans, and these can be converted to disulfides which are much more difficult to eliminate. Left long enough, some batches with sulfur will become unsalvageable.

Providing adequate nitrogen and micronutrients (Pantothenate and Pyridoxine) is key to avoiding Sulfur odor. Proper temperature and pH control may also be helpful. If it still stinks at the end of fermentation, prompt action is called for to eliminate the sulfur compounds.

With all that said, there are some recipes, especially cysers, that often go through a brief "smelly phase" during fermentation that clears without issue.

Medsen

MedsenFey said:

Sulfur odors are not a natural part of mead making.

Sulfur odors, when left alone, may not go away. The H2S may form more complex molecules like mercaptans, and these can be converted to disulfides which are much more difficult to eliminate. Left long enough, some batches with sulfur will become unsalvageable.

Providing adequate nitrogen and micronutrients (Pantothenate and Pyridoxine) is key to avoiding Sulfur odor. Proper temperature and pH control may also be helpful. If it still stinks at the end of fermentation, prompt action is called for to eliminate the sulfur compounds.

With all that said, there are some recipes, especially cysers, that often go through a brief "smelly phase" during fermentation that clears without issue.

Medsen

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Medsen, you are just absolutely stock full of information!
This information about sulfuric smells is good to know, because I've read a thread on here that put me to ease saying that the smell is normal. I believe in my case, that the smell was a result of improper temperature. The smell was very light, not overpowering at all, but definitely present. This was when the must bucket was just in a room, and I believe it was around 75degrees or higher (EEEKS I know). So now I've thrown it in a swamp cooler and the water is holding at about 60 to 62 degrees F. I have not noticed the smell anymore, but that being said I haven't opened the bucket today! In about 15 minutes I'm going to stir the must and get a gravity reading, to see how far along ferm has gotten. Thanks a lot for your quick responses!. :fro: