Actually, if I took it out and left it for 30 days it would still not ferment. When I sealed it, I removed all the air from the container (as prescribed in one of the methods of preservation), I boiled the juice prior to that (another method of preservation). The yeast that causes grape juice to ferment is killed when it reaches a temperature of 176° Fahrenheit. The boiling point of grape juice is 212° Fahrenheit... well above the temperature required to kill the ferment yeast.

So there is certainly no way for it to ferment without the yeast present in it.

And historical records from Pliny, Plutarch, Columella, Aristotles, and other historians of the first Century AD and before can be found in your local library to prove that these methods did indeed keep the grape wine from fermenting. Pliny even recorded that Jews of that day preferred wines that would not intoxicate and considered those who drank the intoxicating wines to be barbarians.

Columella recorded a wine called Lesbian that did not have the ability to intoxicate.

Too many historical accounts to just brush aside because modern dictionaries have changed the meanings of wine to only intoxicating drinks.