Any airtight freezer-safe container will work. I prefer zip-top freezer bags, because they are designed to protect food in the freezer and take up less space, since I can lay them flat, or stand them on end like files in a file cabinet. Fill the bag and then carefully press out all the air as you seal the bag. For extra protection, you can double bag, if you like. Be sure to label the freezer bags and include the date.