Pickling
Keeping food in an acid liquid such as vinegar, or in brine or oil, so that it lasts and turns sharp in taste.
Also: pickle, achar
Pickling preserves food by making it too sour or too salty for spoilage microbes. There are two main routes. In one, the food is covered with vinegar. In the other, it sits in salt or brine and ferments, making its own acid. South Asian pickles, called achar, are often kept in oil with salt and spices. Almost anything can be pickled: cucumbers, cabbage, mangoes, limes, eggs, fish and ginger. A small amount sharpens a plain meal.