Balsamic vinegar, a table vinegar, has a rich, sweet flavor and is an ideal choice to tenderize beef. While you can soak beef in plain balsamic vinegar, the meat will be more tender and flavorful if you use a balsamic vinegar marinade. Either way, marinating beef with balsamic vinegar will combat any toughness and make the cut more enjoyable when cooked.
About Balsamic Vinegar
Balsamic vinegar is made from grape must, also known as grape juice, that has been reduced to a highly concentrated liquid. The liquid is fermented and matured in barrels for at least 12 years, similar to the process of making wine, and when it has finished, the result is a dark syrup with a strong flavor. This true balsamic vinegar is expensive and usually marked as "tradizionale" to signify that it is pure. Most balsamic vinegar you buy at the grocery store is made from a mixture of vinegar and grape must, and it isn't aged for the usual 12 years. It is thinner with a lighter flavor, but it is also significantly more affordable. This thinner balsamic is ideal for marinating beef -- it will still impart the signature flavor, but you won't be throwing away the expensive real thing after soaking the meat.
Why Balsamic Tenderizes Beef
Table vinegars such as balsamic have an acidity of 5 percent to 8 percent. Acidity tenderizes beef by denaturing it, which means that it relaxes the meat's proteins. Relaxing proteins forms pockets in the beef that allow the moisture from the marinate to seep in, making it juicier and more flavorful. As a result of the increased moisture and relaxed protein, the beef will develop a tender texture.
Making a Balsamic Marinade
Soaking meat in plain balsamic can give it a bit of flavor and tenderize the meat, but adding other ingredients to make a complete marinade will enhance the quality. A good marinade needs an acid, an oil and seasonings. The oil moistens the meat and it can soak into the fats in beef, taking some of the marinade's flavor with it. Seasonings such as salt, pepper, herbs and aromatic vegetables such as garlic or onions make the meat more flavorful and will complement the flavor of the balsamic. A simple beef marinade could use balsamic vinegar as the acid, olive oil as the oil and garlic powder for the seasoning. You don't need to use a specific recipe -- just experiment with your favorite oils and seasonings. Make about 1/2 cup of balsamic marinade per pound of meat; use the same portion of liquid per pound if you're using plain balsamic vinegar instead of a marinade.
Time Required to Tenderize
Depending on how tough the meat is when you place it in the balsamic vinegar blend, you should leave it soaking in the refrigerator for between 12 hours and five days. The longer it marinates, the more tender the beef will become. Thicker, larger cuts of tough meats such as beef brisket benefit most from longer soaks, while smaller, higher-quality cuts like sirloin will reach ideal tenderness in 12 to 24 hours. When the beef has finished tenderizing, discard leftover marinade to prevent bacterial contamination.