Nutrients and sulfur smell

[jkrug]

Seems that every time I make wine either from fresh fruit or juice from home winery, I get a sulfur smell. What am I doing wrong? How much nutrient should I be adding? What is the difference between energizer and nutrients? I have a red zin juice I am starting and don't want to have the Sulfur issue. Hoping to add nutrients and yeast today.

 

[cintipam]

I lifted the quote below from Jack Kellar website's page about problems in wine musts.

Another cause of overly sweet wine is a fermentation that stops early because of a lack of nutrition for the yeast. Always add at least 1/2 teaspoon of yeast nutrient per gallon of wine to your must, even if the recipe doesn't call for it. A full teaspoon is often called for in recipes. This amount is usually sufficient

http://winemaking.jackkeller.net/problems.asp

I don't know how to determine if the fruit I'm using provides lots of food for yeast, or next to none, but I assume things like leaves give nothing and simmered bananas give a lot. To be safe I stick to the 1/2 tsp per gallon, but I add in stages. Folks say to add first dose when yeast first starts fermenting, then another dose at the halfway point to dry. Some yeasts are very picky and prone to the dreaded sulfer. I know 71B and Cotes de Blanc to be this way, but there are others. Thats why I split the dose to be safe.

I've read that nutrient is food and energizer is vitamins. I usually add them on alternate days. If that is not a good way to do it I hope someone speaks up and explains why. I'm always hoping to learn more about the whys and wherefores. It's the only way to figure out for myself how to fix a future problem when I have it.

HTH

Pam in cinti

 

[djrockinsteve]

Not knowing your recipe or procedure it's very difficult to diagnose the problem.

There is a Tutorial on basic juice fermentation in our Tutorial section. This should definitely help you. Read that and see if it answers some questions for you.

 

[seth8530]

Hey, give these two threads a look.

http://www.winemakingtalk.com/forum/f86/got-off-phone-fermaid-people-38704/

http://www.winemakingtalk.com/forum/f86/yeast-nutrients-39655/

 

[Julie]

How much nutrient are you adding? And the difference between the two is, nutrient is food for the yeast to eat and energizer is the kick it needs to keep going. In other words, nutrient is like vitamins and energizer is the Red Bull.

Also, how much k-meta are you adding and when do you add it?

 

[jkrug]

I add 1 camp don't tablet per gallon. 1 to nutrient per gallon.

 

[Turock]

Micronutrients are nice to have in a ferment but what is really needed is nitrogen, which is the component you really need in nutrient. Fresh juice musts from fruit are not low YAN (yeast assimiliable nitrogen) musts. So for most ferments from fresh juice, you can assume that the beginning YAN is 150mg/liter. The bare minimum of fermentable nitrogen needed for fermentation is 140mg/L. Normal range is between 225 and 275 mg/L. So as you can see, you need to add enough nitrogen(nutrient) to bring up the YAN to a level where the yeast have the nitrogen that they require.

Yeast energizer--if that's what you're using-- is most effective when added 24 hours after pitching the yeast. Energizer contains Vit. B, DAP, tricalcium phosphate, magnesium sulphate and yeast hulls. Nitrogen is used by the yeast for amino acid generation and phosphate contributes to the energy needs of the yeast. In the absence of enough oxygen-based amino acids, some yeast goes after the sulfur-based ones and generates H2S as a by-product.

So you need to not only give your ferments enough nitrogen, but you need to add it when the yeast is looking for it. As new populations of yeast cells are generated, these new yeast look for nitrogen as part of their nutrient needs. The best way to do this is to step-feed nutrient. Take the entire doseage and divide it in half. With energizer, you'd add the first half 24 hours after pitching the yeast. And the second half at 50% sugar depletion. If you do this, you won't have H2S problems. H2S is almost exclusively a problem of lack of nitrogen--barring any residual sulpher spraying on the fruit in the orchard or vineyard.

Normal doseage of nutrient is 1 tsp. per gallon.

 

[x_diver]

I had a similar problem recently. When I started making wine a little over a year ago, I followed all instructions and all went well. Then as time went on, I would get the sulfur smell on different batches more frequently. Splash racking resolved it but it was really beginning to bug me. I make wine from fruit when available but also from home winery concentrates.

One day, I decided to wash one of my primary buckets with bleach because I thought maybe that campden tablets were not enough. Big mistake. Never do this. The next batch of wine that I made with this bucket had to be tossed.

I then made two changes. I switched to using star San instead of campden tablets to sanitize. And a I switched to using go-ferm / Fermaid-k. Everything else is the same. Since then, I have had no issues.

Not sure which was the culprit, but I have to say that my primary has never gone smoother.


Sent from my iPhone using Wine Making

 

[seth8530]

Micronutrients are nice to have in a ferment but what is really needed is nitrogen, which is the component you really need in nutrient. Fresh juice musts from fruit are not low YAN (yeast assimiliable nitrogen) musts. So for most ferments from fresh juice, you can assume that the beginning YAN is 150mg/liter. The bare minimum of fermentable nitrogen needed for fermentation is 140mg/L. Normal range is between 225 and 275 mg/L. So as you can see, you need to add enough nitrogen(nutrient) to bring up the YAN to a level where the yeast have the nitrogen that they require.

Yeast energizer--if that's what you're using-- is most effective when added 24 hours after pitching the yeast. Energizer contains Vit. B, DAP, tricalcium phosphate, magnesium sulphate and yeast hulls. Nitrogen is used by the yeast for amino acid generation and phosphate contributes to the energy needs of the yeast. In the absence of enough oxygen-based amino acids, some yeast goes after the sulfur-based ones and generates H2S as a by-product.

So you need to not only give your ferments enough nitrogen, but you need to add it when the yeast is looking for it. As new populations of yeast cells are generated, these new yeast look for nitrogen as part of their nutrient needs. The best way to do this is to step-feed nutrient. Take the entire doseage and divide it in half. With energizer, you'd add the first half 24 hours after pitching the yeast. And the second half at 50% sugar depletion. If you do this, you won't have H2S problems. H2S is almost exclusively a problem of lack of nitrogen--barring any residual sulpher spraying on the fruit in the orchard or vineyard.

Normal doseage of nutrient is 1 tsp. per gallon.

Where did you get that it was safe to assume that most must start with an average of 150 mg/l YAN? Just wondering, because if you have a source with average YAN counts that could be quite useful for more detailed nutrient calcs.

 

[Turock]

Seth--I do so much research on things like this, just because I'm an avid student of things that interest me, that I can't remember where I found that info. I remember this white paper saying that most fresh juice musts that most of us use is not considered to be very low on YAN. To really know the YAN, testing needs to be done, which most people don't do. So it's safe to assume that most musts will be around 150mg/L of YAN, and then it's important to get the nitrogen range up to the recommended range of 225 to 275mg/L.

x_diver---The reason you have smoother ferments with Fermaid K is because it's a balance of organic and inorganic nitrogen. DAP is all inorganic. You should never use bleach around the winery. Use good cleaners like PBW for cleaning vats,etc. that need a good cleaner that attacks the crud.

 

[seth8530]

Seth--I do so much research on things like this, just because I'm an avid student of things that interest me, that I can't remember where I found that info. I remember this white paper saying that most fresh juice musts that most of us use is not considered to be very low on YAN. To really know the YAN, testing needs to be done, which most people don't do. So it's safe to assume that most musts will be around 150mg/L of YAN, and then it's important to get the nitrogen range up to the recommended range of 225 to 275mg/L.

Ah, well if you find it shoot it to me. I did some reading and it seemed to me that YAN can vary wildly. I would not mind testing it myself, but to be honest the testing methods seem kind of unsafe unless you are really set up for them.

I think I read somewhere that recommended YAN higher than 225-275 mg/l But it is also highly dependent on yeast strain and the ABV needs of the must. However, to be honest trying to hit a certain target without knowing where you are starting from is kind of a moot point. So then in my mind, it is all about falling on the right side of conservative. So the question becomes, are you better over shooting or undershooting? What are the consequences for both cases?


That being said, meads are nice because you can assume starting YAN is 0.. But, then you get to burn through your Fermaid supply. Which to be honest, I am fine with.

 

[Turock]

It could have come from the Lallemande website. No doubt they've tested a number of varieties of fruit and grapes to come up with that number. And if you think about it, it's undoubtedly the case that most musts are not critically low on initial YAN or many of us would be having problems with our standard nutrition protocols. In 25 years of winemaking, I've never had a H2S problem or stuck ferment because of step-feeding. So I think that's proof of the fact that,indeed, the YAN is not too low to start with.

 

[seth8530]

Well like you said it all depends on the fruit. I have read studies where things like apple juice will range all the way from 50 mg/l up to 300 mg/l yan. Also, I am sure you are mentioning HS2 as the poster child problem of low nutrients, but it is also good to keep in mind that a good nutrient schedule also has other benefits other than avoiding HS2 or a stalled ferment. However, their are also effects caused by over dosing with nutrients, so one must be careful.

 

[garymc]

That concerns me. I don't know if it makes any real difference, but I don't find the idea of drinking wine with extra fertilizer in it to be appetizing.

 

[Turock]

Well, that's why it's important to follow the directions for the different nutrients and not add later than recommended because the older yeast cells can no longer use the nitrogen and it can set the must up for organisms to use it and cause spoilage.