Duck marinade is prepared to tenderize and add and add flavor to the duck meat. When duck meat is allowed to stand in an acidic and flavored liquid for several hours or days, it is known as duck marinade. Marinades help in neutralizing the game flavor that is prominent in duck meat. Basic Italian Dressing is a common marinade. The ingredients required for making duck marinade include dry wine, soy sauce, vegetable oil, freshly cracked black pepper, onion and red wine vinegar.