I did some wild ferments few years ago. The main criteria is if it smells and tastes good.

• lactic smell and taste (like yogurt or cheese) is fine but for some too acidic

• alcohol don’t smell that strong, it is usually just a hint

• fruity and funky notes are good

• vinegar smell is bad, it means you made vinegar

• bad smell and taste like bitter, chemicals or rotting this can be dangerous, but it’s disgusting so you don’t drink it

• …

Try it and you will see.