When your tamales arrive, if they are not frozen, they can be refrozen or refrigerated. In the vacuum-sealed bags, they can stay in the freezer 12+ months and in the refrigerator for 3 weeks.
Here are instructions for re-heating them:
• For steaming, remove tamales from bag, and place in a hot steamer for 15-20 minutes from a thawed state (5-10 minutes more if frozen).
• For oven baking, preheat oven to 325. Remove tamales from bag, wrap in foil, and place them on sheet pan. Bake 15-20 minutes if thawed, and 20-25 if frozen.
• For microwave, cut a hole in the bag. From thawed state, heat one bag at full power 3-4 minutes. If frozen, heat at 50% power 3 minutes; turn the bag over, then heat at full power for 1-2 minutes more.