One of the 1 gallon jugs exploded...!!!

[geek]

From the Merlot blend, I back sweeten one 5gal carboy batch.
All the blend was stabilized (kmeta and sorbate added after degassed), this blend went very dry at 0.994, see log below. I only added 1/2 pound of white sugar and even the log doesn't mention it the SG came up to 1.000

I racked this to 1gal jugs and 2 small bottles.
I just went to the basement to open one of the small bottles and noticed one of the gallon is broken in pieces, the others are ok.

I opened a small bottle and served a glass and did see some sizzling going in the glass.

Please do not tell me that fermentation re-engaged even though sorbate was added per instructions??

What should I do??


Date Time SG
Sept. 25 7pm 1.040
Sept. 26 5pm 1.030
Sept. 27 8am 1.020
Sept. 27 6pm 1.010
Sept. 28 8am 1.008
Sept. 28 12pm Racked
Oct. 05 12pm 1.000
Oct. 06 8pm 0.994
Oct. 07 4pm 0.994
Oct. 08 6pm 0.994
Oct. 09 6pm 0.994
Oct. 12 12pm De-gas k-meta and sorbate
Oct. 15 8pm Fining agent

 

[Julie]

how old is your sorbate and how to you store it? Sorbate has a shelf life of roughly 6 months, if you keep it in the frig you can get a year out of it.

What did you have on the gallon jug? Airlock or a cork?

 

[geek]

I bought this sorbate online maybe 2 months ago and it's been just sitting either in the kitchen or the basement.

The jugs have normal threaded caps.

..

 

[BobF]

I can't tell from your timeline when you added sugar and how long you waited after sweetening before you screwed the cap on. I always leave mine with an airlock for more than one month, usually several.

I have used sorbate as old as 2 years without problems. I store it in a mason jar on a shelf in the basement winery - steady 69-70 temp. It's possible that I'm tempting the fates on the sorbate age.

 

[geek]

Oct. 15 I added the fining agent and waited around a couple days when then I back sweeten a bit in a pail, I racked into the jugs right away and screwed the caps on immediately.

 

[BobF]

That might be the problem. Sorbate does NOT stop active fermentation. Sorbate prevents yeast from multiplying. Whatever yeasts are already there will continue to consume even minute amounts of sugar.

 

[robie]

Sorbate does not kill the yeast, nor does the Kmeta. What yeast were present when you added the sorbate could still attack that sugar and do some fermenting until they die of old age.

I would not have added the sugar, then immediately sealed the jugs with a screw cap. Always keep an air lock on for awhile after modifying the wine.

If you hear sizzling in one of the jugs, it could still be fermenting or maybe even an MLF has started on its own.

 

[geek]

Bob - there was no active fermentation, as i said the wine came down to 0.994 and stayed there 4 consecutive days, it was done..!!

The sizzling was not from the jugs, it was from the small bottle I opened after it and poured wine into the glass..

However, I just opened the other 3 jugs and one is like a volcano..!!
I put an air lock to it and it is really active..!!

The 3rd didn't show much signs of being active and i left the cap a bit lose as i dont have another air lock.

What is my best option now?? Leaving them with air locks?

..

 

[BobF]

Yes, I would airlock them for a while.

0.994 doesn't mean there isn't some small amount of ferment happening, or that it won't restart.

Hydrometers are ballpark devices. They're good for relative measurements to check progress and are pretty close preferment. They are not good for detecting small amounts of residual sugar.

Inherent inaccuracy, temp and alcohol all contribute to their limitations.

 

[geek]

I wonder if I can leave that 3rd jug with a lose cap as I don't have an extra air-lock?

Gosh, lesson learned..!!! Thank God my other demi john and 5gal carboy were not back sweeten, well they could've been ok since they both have air locks anyways.

..

 

[BobF]

I would plug it with fabric or something just long enough to get another bung/airlock.

 

[robie]

I wonder if I can leave that 3rd jug with a lose cap as I don't have an extra air-lock?

Gosh, lesson learned..!!! Thank God my other demi john and 5gal carboy were not back sweeten, well they could've been ok since they both have air locks anyways.

..

Poke one tiny pin hole in one side of a balloon and stretch it over the top of the jug. The tiny hole will close up instantly, and open up if some pressure get into it from the wine. That will work until you get another air lock/bung.

 

[geek]

Thanks guys, I do have extra bungs with the hole but not the plastic air-lock.

sigh.......

 

[geek]

Final 2 questions guys,
1-I assume this wine (now under air lock), will be ok (flavor, aroma) once this fermentation is over

2-how long do you think this fermentation may be over ballpark, assuming I added the sugar around Oct. 20 and keeping the jugs under pressure not breathing?

Basement temp is around low-mid 60s.

..

 

[Tom_S]

I would never cap a jug I've got wine in. Even during bulk aging, the wine is going to have a lot of CO2 in it which will need to dissipate. If you have an airlock on it, it will leave the vessel through the airlock. If the jug is capped, it's like having a bottle of soda. Once enough pressure has built up inside the jug, no more CO2 will leave the wine until the cap is removed. And if there's still a bit of fermentation going on, it's going to build up enough pressure to burst the jug, as you've found.

I remember once putting a solid rubber bung in a jug of wine that I had aged for a while and thought it would have been degassed enough, but the bung popped out several times until I put an airlock back on.

 

[geek]

See this picture of the other jugs after placed with air-lock, there's a bubble formation on the top and tiny bubbles coming down, not a lot of bubbles coming though.....wondering if this batch is still safe ...

 

[GreginND]

As others have pointed out the sorbate doesn't kill yeast, it just stops it from reproducing. Even if the sugar has all fermented out and your SG showed the wine was done, 4 days is hardly enough time for all the yeast to settle out and be gone. It is still alive and waiting for more sugar. I always age and clear my wines at least 3 months - usually 6-9 months - before adding sorbate and sweetening.

 

[Tom_S]

I guess I'm kind of backwards, since I add sorbate & backsweeten before aging.

 

[GreginND]

I guess I'm kind of backwards, since I add sorbate & backsweeten before aging.

That's fine if you've left it long enough to clear as much of the live yeast population as possible. In my opinion, 3 weeks after starting the batch is way too early. There are just too many live viable yeast cells in the wine that will start munching away on the sugar regardless of how much sorbate you've added.

 

[geek]

I got the point about sorbate even before this happened, what I am wondering now is the likelihood of this batch to "survive" and be fine to drink after x time.

I also wonder if I should leave as is in the jugs with air-locks or maybe pour the 3 gallons into a pail and stir a bit and let fermentation finish there, and finally rack back into the jugs?

..