Freeze an uncooked beef roast within three to five days of purchase if you aren't preparing it. Keep it frozen in its unopened packaging for up to a year. If you're freezing it for more than a month, though, protect against freezer burn by wrapping the packaging in freezer paper or aluminum foil or by putting it in a freezer bag. There is a good process for freezing cooked beef roasts, which cannot safely be kept nearly as long. Following the proper procedure helps ensure the beef's taste, coloring and texture are as close to fresh as possible upon thawing and reheating.
Turn your freezer's temperature down as low as it goes three hours prior to freezing roasted beef. Clear as large a space for the meat as possible to maximize cold air circulation around it. The faster the roast beef freezes, the better it will be upon defrosting.
Chill the roast beef in the refrigerator for an hour before freezing. Never put hot or warm food in the freezer, as it can partially or completely defrost surrounding frozen foods.
Cut the chilled roast beef into slices if it is still whole, as thin pieces freeze more efficiently than a large mass. They're also more manageable when thawing and reheating.
Wrap the roast beef tightly in heavy aluminum foil or freezer paper. You can also put it into freezer bags, pressing the air out as you seal the packages. Limit each bagged or wrapped package of beef to two inches thick for efficient freezing.
Place the packages of roasted beef in the freezer. Avoid stacking them or letting them touch each other or other items in the freezer, if possible. They can be stacked or rearranged however you like once completely frozen.
Store cooked roast beef for no more than three months in the freezer.