# Wine taking too long to ferment?



## tacomaguy20 (Nov 28, 2020)

I bought a Juice Bucket of Cabernet and I had it in the primary for a week. Transferred into carboy at 1.006 Specific gravity and in the carboy it's been steadily bubbling but it's been going slow. It's now been just over 4 weeks in the secondary (5 total). It bubbles once every 9 minutes or so. The original fermentation started really early and strong but it's slowed considerably. I haven't tested the gravity again because I wanted to wait for it to finish and didn't want to expose it to more oxygen unnecessarily considering it's got a lot of head space. Was going to rack into a smaller carboy once it stopped. I figure I should just be patient and wait but thought I'd ask the pros. Anybody got any thoughts on this?


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## CDrew (Nov 28, 2020)

It will release bubbles for ages. THat isn't fermentation, it's just CO2 coming out of solution. The only way to know your status is to use your hydrometer. I'll bet yours is long complete.


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## NorCal (Nov 28, 2020)

Check the SG, I agree it is probably finished a while ago and hopefully it hasn’t gone bad.


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## tacomaguy20 (Nov 29, 2020)

CDrew said:


> It will release bubbles for ages. THat isn't fermentation, it's just CO2 coming out of solution. The only way to know your status is to use your hydrometer. I'll bet yours is long complete.



But wouldn't the C02 just escape the wine (displace it) and stay in the carboy's headspace? I assumed the yeast was still going because I thought there needed to be an increase in C02 and the increase in pressure would cause the airlock to bubble. Is that not accurate?


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## NorCal (Nov 29, 2020)

The bubbles are due to CO2. The question is if it is currently being generated by the yeast or simply coming out of solution. Without a hydrometer reading and seeing the SG continue to drop, you don’t know for sure. However due to the info you provided, the thought is that fermentation has completed. The remnant CO2 will protect the wine from oxidation, but I would be concerned about other microbial pressure that could spoil the wine without adding SO2 at this point and most likely racking.


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## tacomaguy20 (Nov 29, 2020)

NorCal said:


> The bubbles are due to CO2. The question is if it is currently being generated by the yeast or simply coming out of solution. Without a hydrometer reading and seeing the SG continue to drop, you don’t know for sure. However due to the info you provided, the thought is that fermentation has completed. The remnant CO2 will protect the wine from oxidation, but I would be concerned about other microbial pressure that could spoil the wine without adding SO2 at this point and most likely racking.



Okay I'll check it. I just never realized the airlock could still bubble after fermentation had stopped.


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## tacomaguy20 (Nov 29, 2020)

Okay SG is 1.003 now so I doubt it's done. My other juice bucket of cab (from the same source) fermented dry to .994. The smell is a little harsh but it tastes okay.


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## Booty Juice (Nov 29, 2020)

It's moving in the right direction.

I'd rack and SO2 into your long term bulk-aging vessel with minimal head space and proceed per your normal methods.


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## tacomaguy20 (Nov 29, 2020)

Booty Juice said:


> It's moving in the right direction.
> 
> I'd rack and SO2 into your long term bulk-aging vessel with minimal head space and proceed per your normal methods.



Wouldn't the S02 make this slow fermentation even worse since the yeast is already having a hard time. I was thinking of adding nutrient to get the yeast going again?


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## Booty Juice (Nov 29, 2020)

That's a logical next step.

For me, I don't worry about slow ferments. I've pressed and carboy'd up to 1.020 and always gone dry eventually - but I also use minimal SO2.

Depending on how concerned you are about a bit of RS - another option would be to wait few days or a week and check the SG again before adding nutrients.

If you're wine isn't stinky, I don't see that you a big problem - but I'd get it into a minimal-head-space vessel ASAP.


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## tacomaguy20 (Nov 29, 2020)

Booty Juice said:


> That's a logical next step.
> 
> For me, I don't worry about slow ferments. I've pressed and carboy'd up to 1.020 and always gone dry eventually - but I also use minimal SO2.
> 
> ...



Okay, thank you. I was also told by another member that once I have it in my long term storage vessel I should rerack every 3 months and add S02. Is that what you do?


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## Booty Juice (Nov 29, 2020)

No - but you're getting sound advice.


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## NorCal (Nov 29, 2020)

It has gone from 1.006 to 1.003 in 4 weeks.....that is very slow. If it were mine, I’d be concerned about spoilage. If it was good clean fruit and you have no off smells now, you could make an argument to let it keep going. You don’t want to add any more nutrient at this point, as you will be providing food for other organisms which can spoil the wine.


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## Booty Juice (Nov 29, 2020)

NorCal said:


> It has gone from 1.006 to 1.003 in 4 weeks.....that is very slow. If it were mine, I’d be concerned about spoilage. If it was good clean fruit and you have no off smells now, you could make an argument to let it keep going. You don’t want to add any more nutrient at this point, as you will be providing food for other organisms which can spoil the wine.



GOOD ADVICE


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## winemaker81 (Nov 30, 2020)

How much sediment is there? If it's more than a dusting, rack off it. Gross lees contains fruit solids which start decomposition when it drops.

I learned something new today -- _fermentation is always anaerobic_. I've been told for years that fermentation in an open container is aerobic while a closed container is anaerobic.

Fermentation (yeast eating sugar) is anaerobic. However, the yeast needs oxygen to reproduce, which is why primary fermentation is normally done in open containers. @JohnT *wrote a good summary* some years back. A quick search turned up several sites that explained in a lot more detail (including the chemistry). However, John's summary is solid and is digestible by folks who (like me) have no interest in revisiting high school chemistry.

Contrary to popular belief, exposure to air during fermentation is not a bad thing. If it was, we'd be fermenting in closed containers. Post-fermentation is a completely different situation, although brief exposure to the air is no where near the danger that prolonged exposure is. This is why we reduce head space as much as feasible.

Racking the wine may introduce enough oxygen to kick start fermentation. Also, put the fermenter some place warm, e.g., 75 to 80 F.


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## sour_grapes (Nov 30, 2020)

winemaker81 said:


> Fermentation (yeast eating sugar) is anaerobic. However, the yeast needs oxygen to reproduce, which is why primary fermentation is normally done in open containers. @JohnT *wrote a good summary* some years back. A quick search turned up several sites that explained in a lot more detail (including the chemistry). However, John's summary is solid and is digestible by folks who (like me) have no interest in revisiting high school chemistry.



WADR, I don't think John's summary is the winner in that thread. I would pay more attention to @spaniel.


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## winemaker81 (Nov 30, 2020)

sour_grapes said:


> WADR, I don't think John's summary is the winner in that thread. I would pay more attention to @spaniel.


Thanks, I'll review the entire thread.


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## sour_grapes (Nov 30, 2020)

winemaker81 said:


> Thanks, I'll review the entire thread.



I should say that I care little about the small semantics question regarding what _exactly_ is meant by an anaerobic fermentation. (I have always used the term the way that John did.) But the part of the discussion that I regard positively concerns when the Crabtree effect is present, and under what conditions the yeast respire aerobically vs. anaerobically.


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## BI81 (Nov 30, 2020)

Hopefully no one takes this as an attempt to step on their toes... for whatever reason this appears to be a touchy topic.

I’m currently taking a wine production course as part of the UC Davis Certificate program and we had a fairly lengthy review on alcoholic fermentation about a month ago...so I do find the subject interesting and would like to attempt to clarify @winemaker81 post above.

Chemically fermentation is a form of metabolism that differs from respiration in that it doesn’t require molecular oxygen. As @spaniel posted MOST organisms prefer respiration because it is much more efficient. However, S. Cerevisiae & O. Oeni are unique in that they prefer fermentative metabolism, even in the presence of oxygen.

S. Cerevisiae can generate as many ATP/sec as are normally generated by respiration. They’re also osmo-tolerant and can multiply many times without oxygen. 

With all of that being said, small (trace) amounts of oxygen favor synthesis of sterols, fatty acids and nicotinic acid. All of which are required for proper yeast cell membrane function. Under normal circumstances oxidation from stemming and crushing is adequate.

(Ronald Jackson, 2020, “Wine Science Principles and Applications, Fifth Edition”, 494-525)


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## winemaker81 (Nov 30, 2020)

BI81 said:


> Hopefully no one takes this as an attempt to step on their toes


Actually, quite the opposite. I learn something new every week on this forum.


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## shoebiedoo (Dec 7, 2020)

I have a similar problem with 2 flextanks of Riesling from buckets. It appears to have stalled at 1.01sg. this product is very good dry and I don't like the slight Sweet flavor. Trying to decide if I should just let it fint it's own way or throw some ec118 and warm it up. 

Thanks


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## tacomaguy20 (Dec 19, 2020)

Hey I thought I'd give an update. I did end up adding yeast nutrient and the wine took off fermenting again. However, it has developed a sulfur smell. From reading this article, There's A Sulfur Smell In My Wine! | E. C. Kraus Wine Making I think it may have been nutrient deficient and the yeast was working too hard to ferment and developed that smell. I just racked adding metabisulfite and causing lots of splashing per the article recommendation. The wine SG is .996 now. I'm going to let it sit in the secondary for a while and see if that helped. I did taste the wine and it doesn't taste bad, just has that smell. I hope it's not ruined. What do you think?


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## CDrew (Dec 19, 2020)

Time to deal with that = ASAP.

Splash rack immediately(sounds like you did that). Maybe copper products like reduless. But it's a serious flaw that you need to correct or dump the wine.

Next year, pay more attention to yeast nutrition and use yeast incapable of producing H2S like Avante or Bravo. I am thinking this is the best option for home wine makers. Personally, I think all the old yeast recommendations are outdated and the no H2S yeasts are the future, both commercially and for home wine makers like us.


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## tacomaguy20 (Dec 19, 2020)

CDrew said:


> Time to deal with that = ASAP.
> 
> Splash rack immediately(sounds like you did that). Maybe copper products like reduless. But it's a serious flaw that you need to correct or dump the wine.
> 
> Next year, pay more attention to yeast nutrition and use yeast incapable of producing H2S like Avante or Bravo. I am thinking this is the best option for home wine makers. Personally, I think all the old yeast recommendations are outdated and the no H2S yeasts are the future, both commercially and for home wine makers like us.



Yeah I never used this yeast before. BM 4x4. I was told it was a nutrient hog but I thought I added enough in the beginning, apparently not. But I did splash rack and I took a sample and left it sit on the counter for a few hours today and the smell had dissipated while it sat so I think I might be alright. Never tried those yeasts before but I may need to now.


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## winemaker81 (Dec 21, 2020)

I had the same problem this year. I stirred the heck out of the wine, and that eliminated most of the smell. There was just a faint bit that we perceptible. I ordered Reduless and it appears to have taken care of the remainder.

The instructions on Reduless said 0.4 to 0.6 grams/gallon. I went middle ground, then hit it with kieselsol/chitosan to help precipitate the result. 

WARNING: H2S is apparently flammable -- if you got it, ventilate well. I opened windows and blew a fan through my wine making area. In addition, this made breathing easier.


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## tacomaguy20 (Dec 21, 2020)

winemaker81 said:


> I had the same problem this year. I stirred the heck out of the wine, and that eliminated most of the smell. There was just a faint bit that we perceptible. I ordered Reduless and it appears to have taken care of the remainder.
> 
> The instructions on Reduless said 0.4 to 0.6 grams/gallon. I went middle ground, then hit it with kieselsol/chitosan to help precipitate the result.
> 
> WARNING: H2S is apparently flammable -- if you got it, ventilate well. I opened windows and blew a fan through my wine making area. In addition, this made breathing easier.



Thanks for the tip. I didn't know about Reduless. If the smell lingers, I'll get some.


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## winemaker81 (Dec 22, 2020)

tacomaguy20 said:


> Thanks for the tip. I didn't know about Reduless. If the smell lingers, I'll get some.


Sniff the wine now. If you smell H2S, order the Reduless. H2S is not a static problem, it gets worse with time and needs to be eliminated immediately.

I had a customer bring in a sample that he'd noticed had H2S a couple of months previously. He thought it would go away, but it kept getting worse. By the time he brought a sample in (I owned a wine & beer making supply shop), the wine was not fixable. He tried racking over a new copper scrubbing pad, but it was a no-go.

_*Note:*_ _At that time_, racking or pouring over copper was the only remedy. Today we recommend strongly against this practice, as wine + copper produces copper sulfate, which is highly poisonous. Products like Reduless enable us to measure the amount going into the wine so we control the situation, and the solids precipitate out.

I used a fining agent to help ensure the copper solids were gone.


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## heatherd (Dec 22, 2020)

tacomaguy20 said:


> Okay, thank you. I was also told by another member that once I have it in my long term storage vessel I should rerack every 3 months and add S02. Is that what you do?


You don't need to rack every three months, but you do need to add kmeta to maintain your SO2 levels. I do that every three months.


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## clusterbuster75 (Feb 9, 2021)

i would not advise adding so2 to a fermenting wine. In my experiences, Some batches take longer to ferment than others, and in my experiences, that isn't a bad thing. I don't add so2 until a wine is done fermenting, then I hit it hard(approx 75 ppm). I check again and if needed, adjust before bottling. I've made a career out of it.


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