Natural Wine

[Andrew Eric Presnell]

Hey guys, I was wondering if a sealed quart jar of Concorde grape juice that’s been sitting in my cabinet for about a year could be turned into wine without the added yeast? Well I guess I was wondering if the Natural sugar would ferment on its own?

 

[franc1969]

I highly doubt it. Well, anything is possible if you have enough yeast floating about to catch your open bucket of juice. You would have to try real hard though- both to catch something that would work, and to Not catch something unpleasant or spoilage organisms. That sealed juice is sterile and won't have any yeast in it like a fresh grape or juice must. Even frozen must has yeast, canned/boxed/ anything prepared from concentrate will not likely result in anything good while you wait.
But I have made a decent first wine from your basic welches juice/concentrate and a yeast package.

 

[Rice_Guy]

*grape thermally processed in a boiling water bath or commercial steam tunnel will not have live yeast. . . . Yeast is relatively easy to kill.

if a sealed quart jar of Concorde grape juice that’s been sitting in my cabinet for about a year could be turned into wine without the added yeast

The primary risk in under processed acidic food is mold, if mold spores were there you will see a mycelia mat floating on the juice. Your second risk is a bad jar seal, ie no vacuum . . . TOSS IT!
Fermented home Canned grape juice is harder to clear than fresh or frozen, use pectase.