Both processes preserve food and prolong its shelf life. Natural preservatives such as vinegar and salt are ideal for these processes. Frequently, they are interchangeable, but they are different. Pickling usually involves submerging food like fruits or vegetables into vinegar or water and vinegar to produce a sour flavor like what they do in canned pickled jalapenos. Here are my pickling recipes you can try: pickled onions and pickled eggs. Fermenting, on the other hand, doesn't usually use vinegar. Salt or salt with water creates an environment for good bacteria to grow. There is no need to add vinegar because the salt draws the liquid out through osmosis, and the resulting lactic acid gives it a sour taste similar to vinegar. The lactic acid then reduces the pH level enough to preserve the vegetables. Kimchi, sauerkraut, and miso paste are popular fermented foods.