Fizzy Rhubarb

Made rhubarb wine from frozen rhubarb last year using dry sugar extraction.
All went well, fermentation straight forward bottled in May this year and put in the wine rack in the cellar.
Went down to cellar saturday morning to get some demi johns and found one bottle had blown the cork (complete with foil cap). On loking at side of bottles saw cloudy deposit like yeast.
So we came to the conclusion it must still be working somehow.
Then the fun started.
All 8 bottles of the stuff back up to the kitchen. Demijohns sterilised, hubby is busy rinsing demis and says to me to take foil caps of. Yeah right !!! Off come the caps then..........6 corks pop out with the force of a launged rocket, this was great fun as between us we had 4 hands and 6 exploding bottles.
Managed to save most of the wine and got it into demis where it started glugging away like crazy.
Did sample a little bit and it's gorgeous, better than real champers.
But the question is what happened. We filtered the wine before it was bottled and it had definately stopped fermenting, could the recent hot weather have re-started it or have we accidently created Rhubarb Champagne.

If there is any sugar left in the wine, sorbate is needed to stop yeast from multiplying any further and more time waiting for the yeast to die off through attrition. Filtering needs to be done with a sterile filter. I use a mini jet with the number 3 pads for any sweet wines along with sorbate and have not had a problem. ALways use a hydrometer to check for signs of fermentation, visable signs are not enough to prevent this from happening.

Just be glad the corks came out and the bottles didnt explode when you were handling them. Regular wine bottles are not designed to hold pressure.

OK,
The problem is really quite simple, there is residual sugar in the wine and once the weather has started to warm the yeast, which is still alive, has started to work again, this time in the bottle,(same principal as in Champagne making.
You need to carefully rack the wine back into a demi-john and allow to ferment out to dryness, SG 995 or below then re-bottle.
You cannot just add sorbate without sulphite or the result will be a "Geraninum" off smell, and taste.
Hope this helps.
C&H,
TC

Unless you have some very good filters, some yeast survived. Rhubarb champaign may not be a bad thing, I'll reserve judgement until next year when I have some.

Sometimes wine is gassy, because co2 is absorbed into the wine, especially when it's been under airlock. The key is to check for the gas before bottling, and degas if necessary. To degas can be a bit of a trick, because you stir the wine vigorously but don't want to oxidize your wine. Some people have wine whips that attach to a drill, and they use that through the top of the carboy to stir until the gas is removed. This should be done very slowly to start, because if the wine has lots of co2 in it, you could get a volcano.

Incomplete fermentation is rarely a cause of this- it's co2 absorption. Bulk aging in a carboy for a long period of time usually solves the problem naturally by allowing the co2 to escape. Of course, if you had sediment too, you probably bottled too soon. You shouldn't bottle until you've had no lees (sediment) for 2 or 3 months and the s.g. is unchanged.

Lorena

Sorry, can'nt buy into the excess CO2 theory, a full fermentation properly completed will ensure the wine has de-gassed.
If, and only if, the wine needs de-gassing, which is a fairly new idea, a few gentle shakes of the demi-john will, if carefully done, remove excess CO2.
But if this is the case, then the fermentation has almost certainly been completed too quickly with a poor formulated recipe which has not included the correct acid/sugar balance.
Any wine that forcibly throws corks or foams is still working, excess CO2 is not the route cause.
TC