Rotten egg smell once again

it seems that no matter what i do I always get the rotten egg smell in my wines. I always manage to get rid of it and everything but its just a pain in the butt to have to splash rack every wine I make. Is there something I can do to prevent this from happening or am i just doomed to splash rack every thing.

Hunt said:

it seems that no matter what i do I always get the rotten egg smell in my wines. I always manage to get rid of it and everything but its just a pain in the butt to have to splash rack every wine I make. Is there something I can do to prevent this from happening or am i just doomed to splash rack every thing.

Click to expand...

What yeast are you using? Red Star Montrachet? You might want to try a different strain or maintain a better nutrient schedule.

pjd said:

What yeast are you using? Red Star Montrachet? You might want to try a different strain or maintain a better nutrient schedule.

Click to expand...

I used EC1118 for 5 gal of skeeter pee. I used 6 tsp nutrient and 2 tsp energizer as per the instructions. Half upfront, half once the SG got to 1.050. mixed twice a day everyday. Been in the carboy for only 1 day and already it has the smell.

What is the iron content of your water? (See http://www.thehappywinemaker.com/Water-in-Winemaking.page)

I really have no idea. This is the very first time i tried using tap water every other time i use bottled spring water.

Maybe you need to do a thorough cleaning of your workspace and equipment.


Sent from my iPad using Wine Making

I keep my area very clean. And sterilize everything that touches the wine including my hands

What bung are you using?


Sent from my iPhone using Wine Making

A special bung made for the better bottles

At what point during fermentation do you detect the smell? If it is at the tail end of fermentation (or when the yeast is settling out), you could try and do an earlier racking.

I'm going to take a stab here. If you're doing the primary fermentation in the Better Bottles I would try a regular normal (fermenting) bucket for the primary fermentation. Better Bottles don't let a whole lot of oxygen in the must while it's fermenting.

Anyway, that's my guess

I have also had more than usual sulphur smell on a few recent batches, and while one was a fresh juice and another a DB... two others were kits! I have been sanitizing everything diligently so the only things I can think of is that I have been used heat belts (still too cold in the garage)... but must/juice temperature never goes over 24/25 deg celcius. I also have been leaving the must/juice in the primary a little too long (to SG under 1.000 trying to maximize extraction of grape skin/must packs). I have a feeling that I am also sensitized to the smell so I may be making mountains out of molehills. Manufacturer has advised me to splash rack and wait it out.

I did use a bucket. Now what I do is place the lid loosely over the bucket. Temp was steady at 72 to 76 degrees

Just for those that do not already know...

That rotten egg smell, H2S, is about 90% time caused by yeast break down and is unlikely caused by any sanitary issue. In other words, cleaning or scrubbing your equipment will not solve your problem.

Quite simply, yeast breakdown occurs when yeast cells are starved for nutrients (especially nitrogen). The yeast cells then devour each other to get at the nutrients they crave.

There are several ways to deal with this problem. First, evaluate the type of nutrient you use and its age. if it is old, then replace it. You may also want to consider adding some DAP (diamoniumphosphate [sic?]) to your must in addition to your nutrient. This will go a long way in "kicking up" the amount of nitrogen present.

You can also evaluate when/how the nutrients are added to your must. Most winemakers use a "feeding schedule", where the nutrients are added in stages throughout fermentation.

Some strains of yeast are very resistant to yeast break down while other strains are very vulnerable. You may want to also consider changing yeasts if all else fails.

Finally, Most cases of H2S that I have come across occur in the tail end of fermentation when you have a thick layer of dead or dying yeast cells. Removing this layer, even while the wine is still fermenting, can also help to prevent H2S issues.

One final note... When it comes to H2s, a little goes a long way. Just 5 part per million can knock you on your back. If caught early, it will not take much to correct the issue. Most see an amazing improvement just by splash racking.

JohnT said:

Quite simply, yeast breakdown occurs when yeast cells are starved for nutrients (especially nitrogen). The yeast cells then devour each other to get at the nutrients they crave.

Click to expand...

Just to clarify: While I agree with the actions John suggests, I don't think this is the actual mechanism for H2S production during the active fermentation.

First of all, yeast autolysis is real, but the key word fragment there is auto-. The way it works is that, for whatever reason, a yeast cell dies. Then the enzymes in the now-dead cell begin to break down that cell. It is not the case that starved, zombie yeast cells start eating the brains of other yeast cells. However, John is correct: if yeast autolysis (especially of a large amount of sediment) is allowed to proceed for a long time, then sulfur compounds may be liberated. But this is different from the H2S produced during an active fermentation.

From my reading of the primary and secondary literature, this is my understanding of H2S production and its relation to N deficiency. Proteins are made of amino acids, and two important amino acids contain sulfur. The yeast has to provide the sulfur to form these compounds to the proper organelle during protein synthesis. It does so in the form of H2S, which it extracts from more complex sulfur-containing compounds. One organelle passes the H2S off to the organelle responsible for protein synthesis.

However, nitrogen is a major component of amino acids (hence the root amine, from ammonia.) If there is a dearth of N, the organelle responsible for synthesizing the sulfur-containing amino acid cannot do its job; this results in a surfeit of H2S, which the yeast then excretes.

As John points out, we are extraordinarily sensitive to H2S and thiols (larger SH-containing molecules). That is why they add a tiny (ppm) amount of methane thiol to your natural gas supply, so that you can smell when you have a gas leak. This is good for gas-leak detection, but the unfortunate result for winemaking is that we cannot tolerate very much H2S excretion by our pet yeasts.

Hope this helps!

The entire problem is caused by low nitrogen. And if your must is very low on nitrogen to begin with, then you might not be adding enough nitrogen--or the correct type of nitrogen at the correct time that the yeast needs it. You need to have a minimum level of fermentable nitrogen of 140mg/liter. A normal range is 225-275 mg/liter.

Now, most of us don't know what our nitrogen levels are in the must. But if you are always having H2S issues, then you know that you have low YAN (yeast assimiliable nitrogen) musts. So you HAVE to adjust your nutrient doseage and/or type of nutrient that you're using. Fresh or frozen juice should have a dose of DAP (if that's what you're using) of 1 gram DAP per gallon. Step-feeding is a must.

But if you are still having H2S issues, quite possibly you should go over to Fermaid K because it not only has DAP--which is inorganic N2--- but it also has organic nitrogen. I've often read that the smoothest fermentations have a balance of organic AND inorganic N2. You should always use Go-Ferm with Fermaid K. And, of course, step feed.

In order to understand this better, go to www.scottlab.com and read about Fermaid products. And if you call them, they will send you a hard copy of their Fermentation Handbook which has lots of useful info in it to help you have smoother ferments. Their number is 707-765-6666.

www.lallamande.com is also a huge source for helping you to better understand YAN. I would suggest you go there and do some reading. That site is a whole wine science source in and of itself.

Information overload lol. I'll take a look at what nutrient I'm using and see what the N content is. It's not old less than 6 months in my possession. I'll also talk with my local home brew store and see about getting better stuff

Thanks for clearing that up SG.

Hunt. Did you check your ph before you started? Sounds like your environment is the problem. Skeeter pee and dragon`s blood and all of its variances have one thing in common because of the ingredients. ACID! Yeast will struggle if your acid is to high. Usually the acid will fall between 2.9 and 3.05. This is a rough environment for yeast.
Post your ph, I am curious to know what it is. Cheers

I would like to know that myself. I havnt gotten a test Kit yet lol