To dry out an Osprey bladder, follow these steps: Empty and Rinse: Empty the bladder of any remaining liquid and clean it with warm water. Use a mild soap if needed. Rinse thoroughly to remove all traces of soap. Air Drying: After rinsing, open the bladder's cap and hang it upside down in a well-ventilated area. Make sure it's fully open to allow air circulation. Use a Drying Rack: Use a drying rack designed explicitly for hydration bladders. Hang the bladder on the shelf, ensuring that the main body and the tube are accessible to air. Keep it Open: Keep the bladder's cap and tube valve open during drying. This prevents any moisture from being trapped inside, which can lead to mold or mildew growth. Patience: Drying time can vary based on humidity levels and moisture remaining. Be patient and give it ample time to dry thoroughly. Check for Dryness: Ensure the bladder is completely dry inside and outside before storing. Condensation or dampness can cause issues if not thoroughly dried. Following these steps, you can effectively dry out your Osprey bladder and prevent mold, mildew, and odor issues.