A tough cut of beef dries out and becomes even tougher if it isn't prepared and grilled properly. Although the amount of fat marbling the beef may give some indication of tenderness, it's the amount and type of collagen fibers that have the most impact on texture. Taking the time to loosen the fibers before you grill results in tender, flavorful steak.
Select the Cut
Beginning with a tender cut meant for grilling prevents tough beef problems from the start. Round and chuck cuts contain more collagen fibers, which soften slowly and aren't meant for quick cooking on the grill. Ribeyes, tenderloins, porterhouse and skirt steaks are usually well-marbled with fat and contain looser collagen fibers so they remain tender on the grill. When in doubt, ask the butcher for recommendations or check the packaging, which often features a label detailing whether the steak is suitable for grilling.
A marinade adds flavor while tenderizing the beef. The right marinade can make even tough beef cuts more tender for the grill. Use a marinade with acidic ingredients to help break down the collagen fibers. Tomato sauce, vinegar and citrus juices all work well. You can also mix red wine, soy sauce or Worcestershire sauce in with the acidic ingredients, as well as crushed garlic, fresh or dried herbs and spices to create a rich, complex flavor. Soak the beef in the marinade in a sealed container in the refrigerator for at least six hours, preferably overnight, so it can tenderize thoroughly.
Pound It Out
Pounding thick, tougher cuts of beef with a meat mallet helps break up and loosen collagen fibers before you grill. You can pound the beef before marinating, after marinating, or even if you decide not to marinate at all. Lay the beef on a cutting board and pound it evenly with the mallet. Flip it over and pound the other side. A properly pounded steak should have an even thickness throughout and should only be flattened to about half its previous thickness.
Proper cooking ensures the beef doesn't get tough on the grill. Heat your grill on high and allow it to warm up for 10 minutes. Sear the steak for 3 minutes on each side, flipping it with tongs or a spatula. After searing, move the steaks to an area on the grill with indirect heat or lower the grill temperature to medium. Grill at this lower heat until the meat is cooked to the desired doneness, as determined by a meat thermometer. Although the USDA recommends cooking beef to an internal temperature of 145 degrees Fahrenheit for optimum food safety, the usual temperatures for various levels of doneness are 125 degrees Fahrenheit for a rare steak, 135 for medium-rare and 140 F for medium. Allow the meat to rest for about three minutes before serving.