Hydrogen sulfide in blackberry wine

[Mallerstang]

I started 3 gallons of blackberry wine in late July, and it developed a strong rotten-egg smell in the primary (I used K1-V1116 plus 4 tsp yeast nutrient). Stirring got rid of most of the smell, so I moved it to the carboy.

Two months later I racked and got a strong smell as soon as the siphon started. After some online research, I poured it between two buckets 10 times and added pot meta. Also we drank a bit of leftovers, which tasted good enough that I didn't want to give up on this batch.

A month later I racked it again, pouring between buckets again and also swishing a copper scouring pad in it for one minute. The smell was greatly diminished, very little sediment, almost clear, and taste was good.

Six weeks later, it's ready to bottle other than a faint sulfur smell if I remove the airlock.

So my question is this - if I go ahead and bottle it, what is the worst that could happen? I plan to age most of it at least six months - any chance the sulfur could push out the corks?

 

[gratus fermentatio]

I've never had this problem, but here's what Jack Keller has to say about it:

"Rotten-Egg Smell: Hydrogen-sulfide gas manifests itself as the smell of rotten eggs. Pour the must or wine from one container to another for a few minutes to aerate it. Refit the airlock and wait a few hours. If the smell persists, repeat the procedure. If the smell persists after four such procedures, destroy the batch."

You might also want to have a look at what Keller has to say about "sulfur" smells:

"Sulfur Taste or Smell: This may occur after treatment with Campden tablets or potassium or sodium metabisulfite. It will disappear with age, but if present upon opening a bottle-aged wine, decant several hours before drinking. To prevent the preservation of sulfur taste or smell, never bottle immediately after stabilizing a wine. See Stopping Fermentation in Finishing Your Wine."

Here's the site address:
http://winemaking.jackkeller.net/problems.asp

Hope that helps. Regards, GF.

 

[Mallerstang]

Hi Gratus - thanks for your reply! I already followed Jack Keller's advice by pouring it between the buckets twice, but didn't want to try it more times than that and risk oxidation.

I think I will bottle it in a couple of weeks, racking it to a bucket first to (hopefully) drive off any remaining sulphur smell. Then I'll stack the bottles sideways in a plastic bin just to be safe (in case it explodes!!) and report back here in a few months with the results.

 

[bernardsmith]

Easier to avoid the problem than to fix it. Hydrogen sulfide is caused by yeast fermenting under stress from lack of adequate nutrition - Not all fruit has all the nutrition that the yeast need so you may want to feed the yeast with DAP or Fermaid.

 

[Mallerstang]

Hmm - I used 4 tsp of yeast nutrient at the start, but perhaps that wasn't enough? Or the problem might be something that came in with the fruit, since apparently yeast can be stressed out by other things. Ripe blackberries are difficult to wash thoroughly, and there always seem to be moldy ones on the bushes (which we avoid of course but the spores might have spread). We pick the invasive Himalayan blackberries along local trails.

Anyhow I've bottled it rather than throwing it out, and it seemed OK. Plan is to age it at least six months. Fingers crossed... Thanks for the help! .

 

[Mallerstang]

Three years later, and I just bottled yet another batch of blackberry with this same problem, which had developed in the secondary fermentation. I did a load of research last spring, and I added yeast energiser as well as yeast nutrient this time, which I think helped but didn't completely prevent it.

I've tried copper before with limited results - racking through a copper scouring pad.

But I'd love to find out exactly what it is about blackberries that gets the yeasties so stressed out! I make wine out of all kinds of things, fruits and juices and raisins and ginger - but it's only the blackberries that have ever had this problem. They are free (though a lot of prickly work to acquire) and make the most delicious wine so I don't want to give up on them. I always rinse them and freeze them immediately after picking.

Has anyone figured this out? Would it help if I avoided primary fermentation in hot weather? Is there a yeast strain that might help? Should I not use EC-1118? Do I need to wash the berries more (or less)? I always use yeast nutrient, and pectic enzyme, but I don't add acid or tannin to blackberries. I use tap water, and the water here is very soft. I don't backsweeten or stabilize.

Help?

 

[Seamonkey84]

Stressed yeast are usually what makes those off flavors or smells. More nutrients and lower temps usually help prevent those problems. Are you stirring and degassing it during primary?

 

[Mallerstang]

Stressed yeast are usually what makes those off flavors or smells. More nutrients and lower temps usually help prevent those problems. Are you stirring and degassing it during primary?

Stirring yes - degassing no, not the fruit wines. I'll give that a try later this year. Thanks for the suggestion!

I'd still love to find out what makes blackberries different from raspberries, blackcurrants, strawberries, blueberries, plums, peaches, cherries - or if anyone else has had this problem specifically with wild blackberries and solved it.

 

[Mallerstang]

Aaaargh - I just racked the blackberry wine that I started in September, and once again it's getting stinky! When should I degas it? I was going to take the advice of Seamonkey84 and degas it in the primary this time, but I forgot. It's gone from primary to secondary plus today's racking.

 

[marcopolis]

The recurrent production of hydrogen sulfide (H₂S) during the fermentation of blackberry-infused beverages is a multifaceted issue influenced by several factors:

1. Sulfur Compounds in Blackberries:

Natural Sulfur Content: Blackberries contain sulfur-containing amino acids such as methionine and cysteine. During fermentation, yeast metabolizes these amino acids, potentially leading to H₂S production. The exact concentration of these amino acids in blackberries can vary based on factors like soil composition and agricultural practices.

Pesticide Residues: If blackberries have been treated with sulfur-based pesticides, residual sulfur can be introduced into the fermentation medium, providing additional precursors for H₂S formation.

2. Yeast Metabolism and Stress Factors:

Nutrient Deficiencies: Yeast requires a balanced supply of nutrients, including nitrogen, vitamins, and trace minerals. A deficiency in these nutrients can stress the yeast, leading to the production of H₂S as a byproduct.

High Sugar Concentrations: Blackberries contribute fermentable sugars, which can increase the osmotic pressure on yeast cells. This osmotic stress can disrupt normal metabolic processes, resulting in elevated H₂S production.

Fermentation Conditions: Factors such as temperature fluctuations, inadequate oxygenation, and pH imbalances can stress yeast, promoting the formation of undesirable sulfur compounds.

3. Chemical Interactions During Fermentation:

Polyphenol Content: Blackberries are rich in polyphenols, which can bind to metal ions like copper and iron. These metals are essential cofactors for enzymes involved in sulfur metabolism. Their sequestration by polyphenols can inhibit enzymatic activity, leading to the accumulation of H₂S.

pH Variations: The acidity of blackberries can lower the pH of the fermentation medium. A lower pH can affect yeast metabolism and the solubility of sulfur compounds, potentially increasing H₂S production.

4. Microbial Interactions:

Wild Microflora: Blackberries can harbor wild yeasts and bacteria. These microorganisms can compete with inoculated yeast strains, leading to incomplete fermentation or the production of off-flavors, including sulfurous compounds.

Microbial Synergy: Certain bacteria can reduce sulfate to sulfide, which yeast can then convert to H₂S. The presence of such bacteria can exacerbate sulfur issues during fermentation.

Mitigation Strategies:

Nutrient Supplementation: Ensuring an adequate supply of yeast-assimilable nitrogen (YAN) and other essential nutrients can help prevent yeast stress and reduce H₂S production.

Oxygen Management: Proper oxygenation during the initial stages of fermentation supports healthy yeast growth and function.

Use of Clarifying Agents: Adding fining agents that bind to polyphenols can prevent them from sequestering essential metal ions, thereby supporting normal yeast metabolism.

Microbial Control: Implementing practices to reduce the presence of wild microflora, such as sanitizing the fruit and fermentation equipment, can minimize microbial competition and the risk of off-flavor production.

In summary, the consistent production of H₂S during the fermentation of blackberry-infused beverages is likely due to a combination of factors, including the natural sulfur content of blackberries, yeast nutrient deficiencies, and specific fermentation conditions. Addressing these factors through careful management of fermentation parameters and nutrient supplementation can help mitigate the issue.

 

[An Ankoù]

The yeast is stressed. A good teaspoonful of nutrient per gallon will sort it out.
I've got some if the yeast used in the 8 year old OP, but haven't used it yet. Not aware of any adverse reports, though. Seems a popular and dependable yeast.
By the way, I made my first batch of blackberry wine at the age of 16. Still making it 50+ years later under all sorts of different conditions and terroirs. Never had sulphur, but I know exactly what the OP is talking about from beer-making.

 

[Miraculix]

If you add nutrient after the yeast did the the work already, the nutrient will stay in solution and make the wine taste bad.

 

[An Ankoù]

If you add nutrient after the yeast did the the work already, the nutrient will stay in solution and make the wine taste bad.

You're probably right when it comes to wine, but I've added a mixture of diamnonium phosphate and ammonium sulphate to smelly beer and it's worked a treat Sure, I know some people's idea of yeast nutrient ranges from vegemite to tomato ketchup and I wouldn't want that in my wine (or my beer), but the inorganic salts are pretty tasteless.

 

[Miraculix]

You're probably right when it comes to wine, but I've added a mixture of diamnonium phosphate and ammonium sulphate to smelly beer and it's worked a treat Sure, I know some people's idea of yeast nutrient ranges from vegemite to tomato ketchup and I wouldn't want that in my wine (or my beer), but the inorganic salts are pretty tasteless.

DAP tasteless? I disagree. That stuff is bad tasting.

 

[An Ankoù]

DAP tasteless? I disagree. That stuff is bad tasting.

I beg to differ. It's described in the scientific literature as a white, odourless powder. I just made a dilute solution of my Youngs Yeast Nutrient and it is, indeed, tasteless. Sure it will give off ammonia under certain conditions which cause decomposition. In any case, if it tainted the wine at the end of fermentation it would taint it at the start of fermentation as we tend to add an excess that is not all used by the yeast.
On the other hand, the wine science community seems to disagree as to whether it is useful in limiting or preventing H2S production and I'll need to have a look at that more closely.