I had to give it a try. I peeled the apples, put it in the jar, poured over some water and left it for 3 weeks. Yes, that's the method and magically vinegar appeared. It is no balsamico by any means but the fun I have while trying makes up for that. I used very green apples for this experiment. Next time I want to find deep red apples and see if that influences the colour and taste of the vinegar.
Did you ever made your own vinegar from scratch? If yes, please share.