Safe Preparation Marinate beef in the refrigerator up to 5 days. Boil used marinade before brushing on cooked meats. Discard any uncooked leftover marinade. Never brown or partially cook beef to refrigerate and finish cooking later because any bacteria present wouldn’t have been destroyed. It is safe to partially pre-cook or microwave meat immediately before transferring it to the hot grill to finish cooking.
(source: USDA.gov)