The flavor of gumbo tends to improve after it sits for a day or two. But you must store it properly to reduce the risk of bacterial growth that can cause foodborne illness. Whether you make it in advance or need to store leftovers, you must cool hot soup before you put it in the freezer or refrigerator.
The Cool Down
Hot food should be cooled to 40 degrees Fahrenheit or below and refrigerated within two hours. To bring the temperature of gumbo down quickly, divide it into smaller portions in shallow containers and cool it for a short time on the counter. Alternatively, immerse the cooking pot in an ice bath, stirring the soup periodically as it cools. Gumbo can be safely refrigerated while it's still warm in shallow, small containers, but you don't want to put a large container of hot soup directly into the refrigerator. Not only will it take too long to cool, it can raise the temperature of the refrigerator and put your other stored food at risk.