A steak can be tenderized using vinegar, according to the United States Department of Agriculture. The vinegar is used to enhance the flavor of the steak, and it is usually added in a marinade that is applied to the steak before cooking.
The acid in the vinegar helps to break down the meat's tissue and allows the steak to absorb more fluid. A vinegar marinade can be prepared using a mixture of vinegar, oil, spices or herbs. The vinegar also aids in the absorption of spices into the steak. A pound of steak requires half a cup of marinade and should always be marinated covered with a lid in the refrigerator.