Yes, cabbage soup can be frozen and will freeze well for up to 6 months. To do so, allow the soup to cool completely, then transfer the soup to a freezer-safe container, such as a glass mason jar, freezer bag, or freezer cubes, to freeze individual servings. If freezing soup in glass jars, make sure to keep the soup below the freezer line. Liquids expand when frozen, and if the jar is filled too high, it can crack in the freezer.