The younger it is the less alcohol it has. I do not consume it for religious reasons so what I've done is this: if it smells like alcohol, pitch it. The only way this has happened is if I've forgotten a jar and let it ferment for a loooooooooong time though.
Kombucha on the other hand always smells like alcohol to me so I've never actually had it. Even tried to grow my own scoby to see if it'd help, it didn't.