Stuck fermentation

[Mricc07]

Hello,

This past year was my first time making wine. I have batch aged a cabernet in a 6 gallon carboy and vacuum sealed it with the AIO pump. I tasted it the other day and realized it is way to sweet and probably didn't finish fermenting. I should also mention that I don't add anything to the wine ( no sugars or preservatives). This batch has been aging since November. How can I restart fermintation without spoiling the whole batch.

Thank you in advance!

 

[Michael T]

Do you have a hydrometer and can you measure the specific gravity?
It may be possible to make another batch that ferments down to bone dry and blend the two batches

 

[Mricc07]

The SG is 1.040. I made other wines this past year and they all came out great. This one seems to have stalled.

 

[sour_grapes]

At 1.040, you may be able to restart this. I would try a starter: Wine Making: Using Yeast Starters For Improved Fermentation . Use a yeast like EC-1118.

@BernardSmith often recommends a protocol even more forgiving than a starter, where you basically continuously add the must to your starter until it is all mixed in to the "starter." Maybe he will pop in to fill in the blanks in my description.

 

[Mricc07]

Thank you very much for the reply. I have been using EC-1118 all along. I will try the steps listed In the link you suggested. My only question is that I currently have the 6 gallons of cab under airlock in a carboy. Would I have to transfer it back to a bucket and expose it to oxygen again ( place cheese cloth over top).

 

[sour_grapes]

Personally, I wouldn't worry about the oxygen exposure if you choose to put it back in a bucket. I don't think it will hurt the cab, and once fermentation kicks off again you will be pushing CO2.

I also think you could, if you so chose, to conduct this second fermentation attempt in the carboy. I suspect that your fermentation will never be a rollicking affair. In case it does, you could reserve a quart or two (like, say, in a mason jar in the fridge) to create more headspace for the fermentation. You could add that reserved juice back into the carboy once the fermentation activity is starting to wind down (at, say, SG = 1.020).

 

[mikewatkins727]

First, I will yield to others with more experience than I have in this area.

This is how I would attack the problem. Transfer the cabernet back into a primary fermenter. create the yeast starter solution and reinocculate the 'must' and proceed forward as if starting from the beginning. I would make heavy use of my hydrometer, thermometer and monitor daily.

 

[salcoco]

the best procedures that I suggest is establish a yeast starter using EC1118. once foaming add one cup of the wine to the starter. once fermenting add two cups again once fermentation add 4 cups keep up process doubling the wine added to fermentation until all used.

 

[winemaker81]

@Mricc07, all advice provided so far is solid. There are multiple options for restarting a ferment.

My question is why did the ferment stop? At what temperature was the wine fermenting at, and what is the storage temperature? Did you have a sudden change in temperature around the time the fermentation stopped? While fermentation can take place at rather low temperatures (below 60 F), I suggest ensuring that the wine is between 72 and 78 F to help the yeast.

During the initial part of fermentation, yeast needs O2 to multiply, so I'd go with @mikewatkins727's advice and put it back in a primary. If the SG was below 1.020, keeping it in the carboy would be fine.

For future reference, use your hydrometer when testing wines, and never count a fermentation as complete without checking the SG. Most wines finish with an SG between 0.990 and 0.996, although sometimes the SG can be a bit above 1.000.

 

[Mricc07]

Thank you all so much for the advice! I will get that back into primary asap and I will report back.

I believe the ferment stopped probably due to temp although the other wines I made came out just fine.

 

[Mricc07]

Something I just thought about re-reading through all your replys. Is it a problem that this juice/wine hasn't been refrigerated in months? I started out making this cab in the garage and it became way to cold ( probably the reason for stuck fermentation). I then moved it to basement which is usually a constant 65-75 degrees and it has been sitting there for months.

 

[Mricc07]

Also, I was checking SG with a refractometer and it said 1.040. I just checked with an actual hydrometer and it's saying 1.000. This wine is still crazy sweet. Anything I can do to this wine at this point? Thank you and sorry for all the questions. I appreciate all the help you have provided!

 

[winemaker81]

@Mricc07, the devil is in the details. Your latest posts change things greatly.

First -- what does the wine smell like? If there are sour, off-smells, you may be SOLF on this one. If it smells ok, you may be fine.

Chances are the cold temp stuck the fermentation. If it sat there for months, moving to a warm place may not got the fermentation going again. If the wine was under vacuum during the interim, it may be ok.

A refractometer works on grape juice. Once the must starts fermenting, the alcohol changes the result, so you must use a hydrometer.

1.000 should not be "crazy sweet", but the perception in a Cab Sauv may be so.

At this point, I have NO idea what your wine will produce. My best advice is to try to restart the fermentation, if you can. Time will tell.

For future reference:

• Take a hydrometer reading each time you touch your wine. If you need help, this is an essential piece of information.
• Include all details from the beginning. You may not know what matters.
• Don't give up. Everyone has things go wrong, and sometimes we can fix them.

 

[Mricc07]

The wine has a very strong alcohol smell. Tastes good just very sweet. I like my wine dry. Do you think I should pitch yeast to it and if so should I put it under airlock or leave the carboy open and covered with cheese cloth?

 

[winemaker81]

The wine has a very strong alcohol smell. Tastes good just very sweet. I like my wine dry. Do you think I should pitch yeast to it and if so should I put it under airlock or leave the carboy open and covered with cheese cloth?

Strong alcohol smell? What was the OG?

Perception of sweetness is a personal thing. I backsweetened a mead to 1.003 and thought it was almost too sweet. Other folks backsweeten to 1.040 and call it good. My guess is your perception is like mine, so 1.000 for a dry red ... is not a dry red. You will be surprised what a drop of 0.004 will do to a red.

While a SG of 1.000 shouldn't matter in terms of closed or opened container ... my gut feel is to create a good starter and put it in an open bucket under a towel. I don't have a good reason for suggesting that -- it's simply what *I* would do.

 

[mikewatkins727]

@Mricc07, the devil is in the details. Your latest posts change things greatly.

First -- what does the wine smell like? If there are sour, off-smells, you may be SOLF on this one. If it smells ok, you may be fine.

Chances are the cold temp stuck the fermentation. If it sat there for months, moving to a warm place may not got the fermentation going again. If the wine was under vacuum during the interim, it may be ok.

A refractometer works on grape juice. Once the must starts fermenting, the alcohol changes the result, so you must use a hydrometer.

1.000 should not be "crazy sweet", but the perception in a Cab Sauv may be so.

At this point, I have NO idea what your wine will produce. My best advice is to try to restart the fermentation, if you can. Time will tell.

For future reference:

• Take a hydrometer reading each time you touch your wine. If you need help, this is an essential piece of information.
• Include all details from the beginning. You may not know what matters.
• Don't give up. Everyone has things go wrong, and sometimes we can fix them.

Please Click to Expand. I added the emphasis because that is so important. Personally I would reverse the order they are listed for importance.