View Full Version : Recurring Sulfur Aroma Issue

07-05-2015, 04:30 PM
I keep producing meads with a slight sulfur aroma during fermentation, and at first I figured it was due to low nutrients levels, since that seems to be the most common cause in mead. However, no matter what level of nutrients I add, the sulfur aroma is still there. Then I thought it might be temp control; yet that doesnít seem to have solved it.

Iíve included my standard mead making process below, any help or insight is much appreciated:

1 gallon:
-OG of 1.095 (usually orange blossom honey)
-Add 1g K2CO3
-Oxygenate must for 30 seconds with pure O2 (diffusion stone)
-Add 5g dry yeast, usually 71B or Rhone 4600
-Standard yeast rehydrated process using Go-Ferm protect
-After lag phase I ferment at 62 degrees F in a chest freezer

My SNA procedure is a combination of Fermaid O, Fermaid K and DAP to get a YAN of 350 ppm for 1 gallon of must. I usually add about 20% of the Fermaid O in the must prior to pitching the yeast, and then split up the rest of the nutrients into equal additions at 24, 48 and 72 hours.

I use an airlock at all times, and aerate the carboy by shaking it twice a day for the first three days.

Any ideas on what could continually cause the sulfur aroma? I know Iím overpitching the yeast, as I usually use the entire 5g yeast packet for 1 gallon. Could that be the problem, since my nutrients are based on a normal pitch amount? Any other ideas?



07-05-2015, 06:21 PM
I think 5 grams is "standard" for pitch rates for a gallon batch. It certainly wont hurt anything and in my opinion there are many positives for using that much. I have never tried Rhone 4600. The handful of times I have used 71-b I get the same results as you do. I'm starting to lose faith in that yeast. I too control pH, temps, oxygenation, degassing, sanitation and SNA's. Using Fermaid -O, or Dap and Fermaid-K turns out with the same results.

You need to rack enough to not let it sit on the lee's very much. Even knowing that I still get sulferish stink. I have asked around and tons of peps like it.

Chevette Girl
07-05-2015, 08:29 PM
I'm presuming the smell goes away by the time fermentation is done and you're racking it to secondary?

If you don't open your carboy to atmosphere when you're aerating it during fermentation, all you're doing by shaking it is degassing, not aerating or oxygenating it. Most of the sulphur smell problems I've had have been corrected by a good splash racking or aerating the crap out of it. It may be that your must needs another shot of oxygen mid-fermentation. I'm not sure how feasible that is with a diffusion stone in a fermenting must in a carboy (I don't know how much degassing you'd have to do to make it a safe endeavour!) but that's my guess on it.

I'm pretty sure that overpitching isn't your problem, all that does is save a few doublings in lag phase and I think thetre are a few folks around here who routinely overpitch and haven't reported this particular issue as a result.

07-05-2015, 08:41 PM
One of the mead makers at Meridian Hive Meadery in Austin, Texas suggests this for the sulfur/rotten egg smell in a mead:

For a 5 gallon batch, boil 1 Tbsp of bread yeast in 1 cup water in the microwave. Add to fermenter along with 1/2 tsp Fermaid K. Mix and degas until smell returns to a clean honey aroma, about 5 minutes. Naturally, modify the amounts to suit your batch size.

07-05-2015, 09:37 PM
Two things.

I always use a stone and oxygen to oxygenate my wort and must. However I always stir it first to make sure it is completely degases before I turn on the oxygen, otherwise it can do a pretty good imitation of Mt. Vesuvius.

As to "Over Pitching", theoretically you can, but as home brewers we are generally always under pitching yeast, so our "over pitching" iis usually just under pitching, but not by as much.

A Theoretical ideal pitch would be some where in the neighbor hood of:

1 million cells * Milliliters of wort * degrees Plato

Now the reasons for pitching this much yeast is that it is near the maximum amount before you start to get any negative problems from pitching to much yeast (and you you can pitch to much yeast) but because breweries (and I assume meaderies) tend to re-use their yeast they want to make sure they have enough to out compete any other organisms that might have have found their way into their yeast. I know that my friend that owns a craft brewery says that he only buys new yeast of his standard strain once about every 6 months.

Remember though that many of the flavors that people are looking for from your yeast come from the growth of the yeast. So less growing, less esters for flavor. Depending upon what you are looking for this could be a good or a bad thing.

So for you batch that would come to about 435 billion cells or so that you could safely pitch.

Most dry yeast is only about 20 billion cells per gram (if you pitched it dry without re-hydrating it first you kill about 50% of the cell). So even with proper re-hydration (without making a starter) you were only about 20% of the way before you might expect to see any potential problems from over pitching your yeast.

Just for Comparisons, I usually make a 2 Liter starter and that should give me around 250 billion cells for my 5 gallon batches.


07-06-2015, 08:14 PM
Thanks all! Glad to know overpitching is probably not the issue. Chevette Girl, yea I do open the carboy to let O2 in when aerating, and I've done it 2-3 times a day for this batch (for the first three days), so I'm assuming O2 isn't an issue. But I may try adding pure O2 this evening and see how it turns out. The sulfur aroma has been present in previous batches even after racking so that's why I'm worried about this batch- but it's still early, so maybe it will just dissipate naturally.

07-07-2015, 08:24 AM
I typically aerate with oxygen through a diffusion stone once a day for the first 4 days of fermentation, degassing first. I also leave the lid ajar so that air can get in easily during that time. I'll seal things up after a week. I can't say that this will solve your problem since I haven't faced the same problem, but I can say it's worth trying. The worst that will happen is that it won't help, but it also won't hurt.

Kansas Mead
07-07-2015, 03:21 PM
Have you tried a copper scrubber? I use one in a five gallon ferment and after two days the sulfur was gone.