/diy/ - Do It Yourself

You can't just close it up because it WOULD explode. You need a little device like in this picture. It lets carbon dioxide escape without letting anything in. It's POSSIBLE to ferment something without it, but it's not a good idea. If you get fruit flies in it, it will turn to vinegar.

That said, I don't know if it will work. I just no it's not as simple as throwing in yeast and closing it up. I've helped make wine from scratch and it takes MONTHS, but that's with two rounds of fermentation. If it doesn't go right, it could make you quite sick.