According to the Apple Green Health Network, there are several ways to preserve fresh milk fans:

1. Dry and ventilated storage: Place the milk fans in a cool, ventilated place. Avoid direct sunlight and humid conditions. This method can keep the breast fan for about a month.

2. Vacuum packaging or plastic wrap sealing: If long-distance transportation or long-term storage is required, the milk fans can be vacuum packed or sealed with plastic wrap. This allows the breast fan to be stored for one to three months.

3. Refrigerated storage: Place the milk fan in the refrigerator compartment and keep the temperature below 6 degrees Celsius. This method can extend the shelf life of milk fans.

4. Store in low temperature and protected from light: Place the milk fan in a backlit cellar or a storage room that is protected from light and low temperature. This method can extend the shelf life of the milk fan.