My parents have just made a batch of pickled gherkins. Strangely, the vineger they used was brown prior to being added to the gherkins but is now clear and slightly greenish. Does anyone have any idea why?
Have the pickles changed color? Did anything settle out?
While it is possible that a chemical reaction took place, but my first instincts would be for something more obvious. PH can certainly change the color of many molecules like anthocyanines (which I will bet your vinegar had) in foods, but the pH likely didn’t change all that much.
Whatever substance was causing the brown color in the vinegar (not vineger) was probably absorbed by the pickles, leaving the vinegar clear.