Helppp! Homemade Wine!??

Question

Okay so my dad made wine for the first time this year. With the help of his friend who has made it a lot in the past. He bottled it about a month ago and is keeping it in the cold room. Since then about 15 or more bottles have been exploding. The cork is popping off and the wine is going everywhere. Basically making a huge mess and a big hassle. Anyone know why this might be happening?

Answer 1

While primary fermentation could be the problem (i.e. not all sugar was converted to alcohol) it is doubtful if he made it with an experienced friend.

It is more likely he has some sort of microbial contamination causing a "secondary fermentation"  of the acids in the wine.  The bottles may make it through the process without all of them blowing, but when opened, they will have a slight fizzyness not unlike champagne.  Unfortunately, there is not a lot he can do about it short of opening all the bottles and pouring them back into a larger vessel.  Then he should sample the wine and take it to his local homebrew shop to help him figure out what is going on.

Answer 2

He didn't ferment to completion. If it is supposed to be a dry wine, put all the wine back into the fermenter and let it work until the airlock stops bubbling and the specific gravity remains constant for three days. If it is supposed to be a sweet wine, he forgot to stop fermentation with metabisulfite. That should be done before he re-bottles. Also, look at the necks of the bottles. If there is a ring of crud in there, it is likely that the procedure was less than sanitary and he got bacterial fermentation. The whole batch could have been ruined. I hope it isn't that.

If I've solved the problem, I expect you to hoist a glass for me.

Answer 3

not stopping the fermenting in time... you have to use an acid or other chemical to stop the fermentation before corking your wine... otherwise the bacteria will continue making alcohol from the sugars long after corking, causing a CO2 buildup to the point they will explode.

most people that are making wine use campden tablets, available online or many stores.