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I started this sub Forum because a number of us are experiencing H2S with the 2016 fermentations. This is usually a sign of insufficient nutrients. Peter has generally experienced fewer problems when vitamin B5 (pantothenic acid) is also added to the must at the onset of fermentation.
If you are having H2S problems, post your experience here: the varietal with the problem, what steps you took to correct the problem, whether you were successful, etc.
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Hi all,
H2S problems should be rare. I have experienced them occasionally when I leave my new wine on the gros lees for too long. It is very important to check the wine at least twice a day for H2S. At this stage, it is easy to remove the problem by racking and splashing. O2 will rid you of the problem in most cases. If not, then a stir with a copper pipe helps. If you allow the disuphides to form then it’s a whole different problem.
I have noticed that many club members use a lot of sulphite on their crushed grapes. This too can lead to H2S problems. Use only the minimum amount. In my experience, it is rare that the grapes we receive require much sulphite at all and sometimes they have residual sulfur left over from from dusting. I often use none unless I intend to cold soak for more than two days. I have seldom had any problems.
Causes of H2S also include such things as poor sanitation and lack of proper nutrients. If you use Go Ferm or equivalent to start the yeast then you should have enough nutrients to start the fermentation until it is at least 1/3 complete. At which time, you should be adding additional nutrients such as Fermaid K and DAP.
Generally I assume a YAN of 150 without any lab results but I agree with Dave. And, adding too many nutrients can be as bad as not adding enough. Especially if you add them late in the fermentation.
Good luck,
Mickey Bliss
These are my experiences after 20 years of making good quality wine.
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The 2016 spread sheet does calculate lower values of YAN especially at high Brix values then the 2015 version. I did this because Scott Lab Handbook recommended this. This may be because they are promoting Fermaid O as a more complete nutrient utilized by yeast more efficiently.
Syrah, Pinot Noir, and Chardonnay are prone to H2S so it pays to be more vigilant. My syrah showed signs of ferment right after the crush so I flooded the primaries with CO2 and warmed the must for early pitching of cultured yeast. I also assumed that the wild yeast consumed most of the nutrient. I did use my spread sheet for the syrah. I used two yeasts, Clos and BDX and added 125 mgN/L (13 g Fermaid K and 33 g Fermaid O) with 117 mgN/L supplied by the grape. The must aroma is pleasantly fruity so far.
Kloecker / Hansenia tolerates 70 ppm SO2 and is naturally cold tolerant while Saccharomyces is not—it has to acclimatise. Kloecker will consume B1 in just a few hours.
When the yeast is under stress and throwing off H2S adding DAP (inorganic nitrogen) may in fact increase the problem because the yeast being deficient in vitamin B5 will not be able to use it without producing more H2S and volatile acidity. A capsule or two of B5 is beneficial if inorganic nutrients like DAP and used.. I always add it.
Dominique Delteil offers the following advice. Opti-Red or BoosterRouge at 300 ppm plus ascorbic acid at 10 ppm stirring every other day for a week. Then rack without aeration. Sometimes you need a second treatment if you want to avoid copper treatment. -
This year I experienced H2S with the Pinot Gris and the Pinot Noir. In the case of the Pinot Gris (PG), it showed up the morning after pitching the yeast. This surprised me because the PG was supposed to have a grape YAN of 178 mg N/L. Should have been plenty of nitrogen to get the ferment going. At any rate, I added my first set up nutrients which included Fermaid K, Fermaid O, and DAP. The H2S cleared up within 2 hrs of this addition and has not come back.
In the case of the Pinot Noir, the H2S showed up on day 3 of the ferment at an SG of just above 1.050. I added my 2nd set of nutrients and aerated with my punch down tool but the smell persists through day 4. So, on day 4 I doubled up on the dosage for my third feeding. Again, within a couple of hours the smell was gone and the must smelled sweet as it should.
In 2014 I had a Gewurtz ferment where the H2S just didn’t clear up. I tried dumping from one primary to another, running the juice through a large funnel with copper mesh in the spout, blowing through a tube into the juice (this technique from Duane), and in the end I was stuck with stinky wine. I ended up treating the wine with copper sulphate, waiting a week, racking off any copper precipitate, then filtering. After all this, the wine turned out pretty good (no hint of H2S)
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Much of the well researched articles in the Nanaimo Winemakers website are owing to the time and efforts of former member Rod Church. Members can find an excellent article on dealing with H2S issues by clicking on WINEMAKING | VINTNERS CORNER | Understanding Sulphur Defects in Wine. There you will find an excellent article by Rod on this topic, and instructions on steps to take if you experience H2S during fermentation or in the finished or near finished wine (the steps taken differ depending on the stage of fermentation).
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Much of the well researched articles in the Nanaimo Winemakers website are owing to the time and efforts of former member Rod Church. Members can find an excellent article on dealing with H2S issues by clicking on WINEMAKING | VINTNERS CORNER | Understanding Sulphur Defects in Wine. There you will find an excellent article by Rod on this topic, and instructions on steps to take if you experience H2S during fermentation or in the finished or near finished wine (the steps taken differ depending on the stage of fermentation).
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My Syrah has developed H2S two days ago, on Day 3 of fermentation. I added Fermaid K on Day 3 and DAP on Day 4. The smell seems to have diminished today (Day 5), but not gone yet. Brix is 10. Will add more nutrients today and aerate. Can B5 still be added at this stage or is it too late?
The strange thing here is that I am fermenting 200lbs of must in two containers. 3/4 of it in my 20 gallon bin and 1/4 in the smaller 10 gallon. The HS2 developed only in the the larger one and the smaller one smells sweet.
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