[Muc]

Anyone got any experience of making vinegar?
John Seymour recommends dripping wine/cider through wood soaked in natural vinegar so the vinegar bacteria can get to work.
I've tried collecting that last inch from wine bottles and mixing it with a little balsamic vinegar and letting nature get on with it. It tastes vinegary but I'm not sure if I'm just tasting the starter vinegar.
Has anyone done this successfully as Mrs Muc's 'book' club leaves a lot of nearly finished bottles after discussing the latest page-turner.