Wine, Malt and Cider Vinegars
The easiest way to make vinegar is to simply start with your left over bottles of wine, beer or cider. On my fermenting shelf in the kitchen, I usually have a few different things on the go - usually white wine vinegar, as we always seem to have half bottles left (which is good as its my favourite vinegar for salads).
Leftover wine, beer or cider
optional: raw vinegar as a starter
Fill a glass or plastic container about half full with what you are planning to turn into vinegar - shallow bowls work great here, as they maximise the surface area.
Optional: Add about 1/4 of the volume of raw vinegar or a vinegar mother (store bought or some left over from your last batch are all fine).
Cover with a cloth to let air in but keep flies out.
Ferment in a warm place for 2-4 weeks.
Start taste testing your vinegar after about 2 weeks. When it hits your preferred level of vinegary, you will need to bottle it to stop further acidification.