Foods are preserved in vinegar in an attempt to lower the pH, which can prevent the growth of food-spoiling microbes. The acidic environment created by vinegar reduces the enzyme activity of food-spoiling microbes.
Vinegar is great for preserving foods, such as meat products, fish, fruit and vegetables. Preserving foods in vinegar is typically done by the process of pickling, which is an ancient food preservation process. Ancient people explored ways to pickle foods to preserve them for long winters, famine or other times of need. For instance, workers building the Great Wall of China ate a form of fermented cabbage. This process may have originated when food was placed in beer or wine to preserve it, since both have a low pH.
Containers have to be made of glass or stoneware; vinegar would dissolve the metal in pots. In the 16th century, food preservation became more popular with the arrival of new foods to Europe. Sauces were made from the pickling juices by adding spices. This is where chutneys, relishes, piccalillis, mustards and ketchups came from. Worcester sauce developed after a barrel of special relish was accidentally forgotten and aged for many years in the basement of the Lea & Perrins chemists' shop.