Several factors influence the tenderness of a steak. Sometimes, it's not readily apparent from the appearance of the steak in the package at the store that it's not as tender as you'd like it to be. Commercial meat tenderizers are available at most grocery stores, but you may not know you'll need one until you get home and discover you bought a steak that needs tenderising, and you may not have any tenderizer on hand. Fortunately, there are many home remedies for tenderising steak, one of which is vinegar. Pour it on the steak and the acetic acid in the vinegar will break down the tough tendons and make the steak much more palatable.
Mix 1 part vinegar and 2 parts of a warm liquid such as beef or vegetable stock or oil (enough to coat all of the steaks) in a glass or plastic bowl and stir well. When you tenderise using this method, you can also use this liquid to marinate your steak. Consider adding herbs and spices to the mixture to add flavour to the meat.
Pierce the steak in several places on both sides with a fork. The holes will allow the tenderizer to penetrate the interior of the meat.
Place the steak in the vinegar mixture. Massage the meat and turn it back and forth to make sure that it is well coated in the tenderizer.
Place cling film over the bowl. Place the meat and tenderizer in the refrigerator for at least two hours. The longer you keep the meat in the tenderizer, the more tender it will be.
Remove the steak from the tenderizer mixture and prepare it as usual.
Never use a metal bowl to marinate steak. The vinegar in the marinade will react with the metal of the container.