Final answer:
Vinegar is a food product traditionally made through acetic acid fermentation of cider and honey, resulting in a solution with 4%-10% acetic acid, giving it its sour taste.
Step-by-step explanation:
An example of a traditionally preserved food product made by using acidic acid fermentation is vinegar. Vinegar is created through the fermentation of cider and honey in the presence of oxygen, a process which transforms ethanol into acetic acid. Acetic acid fermentation produces a solution containing 4%-10% acetic acid, contributing to vinegar's distinctive sour taste. The fermentation process is also used to make other fermented foods such as sauerkraut, cheese, and yogurt, where lactic acid bacteria thrive and create the acidic conditions that are characteristic of these foods.