Marinades are a centuries-old way of preparing meat. They were first used in the Renaissance to make meat juicier or to mellow the flavor of game. Today, marinades are generally used to bring out the flavor of the meat. An ideal ingredient for this purpose (among many other uses!) is apple cider vinegar.
As a powerful bactericide, it helps eliminate any impurities in the meat. Throw in some sage, rosemary and chopped garlic and you’ll have an excellent light marinade that won’t mask the flavors of the meat, but will instead bring out the best in it to dramatic effect. You can also use it to make a sauce to accompany dishes or, for roasts, to keep basting the meat to stop it drying out.