Once cooled, freeze meatballs in a ziplock freezer bag. Squeeze out all remaining air and seal. Make sure to date and label. (Note: Freeze in bag/number size of your choice for easy thawing). To thaw place the bag of meatballs in the refrigerator in the morning and they will be thawed by dinnertime. The frozen meatballs can also be put directly into your sauce and simmer for 15 to 20 minutes.