Hi gther,
Vinegar is 5% Acetic Acid (CH3COOH)
If you r seeking natural production ,it is by aerobic fermentation so that the sugar breaks down and fully oxidizes
to CH3COOH..enhanced oxidation ,and mixing speeds up the cycle..start with KIrk-Othmer encyclopedia..ofcourse the internet is your best bet..Also you will find the industrial methods from hydrocarbons..