Dear Wine Wizard,
I made 15 gallons (57 L) of wine in my basement and it won’t finish fermenting. Now I am left with a wine that is carbonated, which I do not mind. The problem is that when I store them on their sides, they start to bleed through the corks — two even popped out of the bottle! So the taste I don’t mind, but how do I store these bottles? Will they all eventually just explode? Would it be a good idea to start drinking them sooner as opposed to later? I was thinking of adding a stabilizer in each bottle and then recorking them. Would this work or should I just keep the wine stored upright? Also, I started on 15 more gallons (57 L) of wine in my basement not knowing that this problem would exist. Since then I have wrapped the carboys with blankets hoping that they would retain enough heat for a good fermentation. Is this a good idea or should I move them upstairs?
The Wiz Responds: Ah, the joys of an incomplete fermentation. I’ll start by answering your last question first. Yes, moving your carboys to a warmer place is a very good idea. I don’t know the average temperature in your basement, but it’s likely that — if your basement is below 55 ºF (13 ºC) — cooler temperatures did contribute to a slow-down and the eventual sticking of your fermentation. Most yeast become sluggish (some can even start shutting down) if their ambient temperature of the wine drops below 55 ºF (13 ºC). It’s a good idea to check with the manufacturer for the specific characteristics of your yeast strain, but most commercial yeast strains are happiest in a 60–80 ºF (16–27 ºC) temperature range.
With regards to your 15 gallons (57 L) of wine that still has residual sugar — the approach you take will depend on how much of an interventionist you want to be. You obviously have some residual sugar or malic acid that is still getting consumed by yeast or lactic acid bacteria. The organism or organisms still living in your wine are producing carbon dioxide gas as they finish out the fermentation in the corked bottles, causing the perceived spritziness in your wine as well as the popping of your corks.
If, as you say, you don’t mind the fizziness and find that standing your bottles up rather than storing them on their sides keeps the corks from popping, go ahead and store them upright. Since this wine seems to be relatively unstable and not meant for long-term aging anyway, I wouldn’t worry about the corks getting dry as they’ll be fine by the time you drink it.
Long story short, it’s best, as we all know, to start with a good, healthy and strong fermentation that will finish itself out. I think that moving your current vintage up into your house to a warmer locale is a good place to start your troubleshooting.