The real problem comes in trying to make more, in a post-TEOTWAWKI world it could be a challenge.
Vinegar is made by having a bacterial colony, called a vinegar mother, metabolize the alcohol into an acid. Well, first you need alcohol like wine (red and white wine vinegars) or spirits (distilled) or even beer (malt).
Generally, you need some yeast to convert starch from grain into alcohol and plenty of clean water.
But first you need a lot of excess grain or fruit to create the alcoholic beverage first and that requires lots of land and water and seeds and farming equipment.
A logistical challenge.