Many types of fish, including herring, lake trout and salmon, are excellent sources of omega-3 fatty acids, which will reduce a person's risk of cardiovascular disease according to the American Heart Association. The use of buttermilk is an effective and tasty way to tenderise fish, which is difficult to tenderise otherwise by beating it with a meat tenderising tool. The acids founds in the buttermilk will break down the fish, making the finished product more tender and delicious.
Pour 2 cups buttermilk into a zippered plastic bag. Use a larger bag if you are marinating several pieces of fish.
Place the fish into the bag and close it tightly, paying attention that all of the fish is submerged in the buttermilk.
Store the fish inside the refrigerator for 10 to 15 minutes. According to Fine Cooking, fish does not require an excessive amount of time to tenderise in the acidic buttermilk.
Remove the fish from the buttermilk and rinse under cool water, if desired. Otherwise, leave the buttermilk as a layer of flavouring when preparing the fish.
Pour the buttermilk down the drain and throw out the plastic bag. Do not reuse the buttermilk to tenderise any other cuts of meat.