The presence of water droplets on the outer periphery of bottles taken out from the refrigerator, even when the outside conditions are dry, is due to a phenomenon called condensation. Condensation occurs when warm, moist air comes into contact with a colder surface, causing the moisture in the air to convert into liquid water droplets.
Here's how the process works:
Refrigeration: When you place a bottle in the refrigerator, it becomes cold due to the low temperature inside the fridge.
Moisture in the Air: The air inside the refrigerator is generally cool and has low humidity. However, when you take the cold bottle out of the fridge and expose it to the warmer ambient air outside, moisture from the surrounding air can condense on the colder surface of the bottle.
Temperature Difference: The surface of the bottle is much colder than the ambient air, especially if the refrigerator is set to a low temperature. As a result, the warm, moist air that comes into contact with the cold bottle rapidly cools down, and its moisture condenses into visible water droplets.
The same phenomenon often occurs with cold drinks on a hot and humid day. You might have noticed water droplets forming on the outside of a cold drink glass in warm weather.
To prevent or minimize condensation on the outside of bottles, you can try the following:
Allow the bottle to acclimate to the room temperature for a short while before opening it. This reduces the temperature difference between the bottle's surface and the surrounding air.
Use an insulated bottle or a koozie to help maintain the bottle's temperature and reduce the chances of rapid condensation.
Keep the refrigerator door closed as much as possible to maintain stable internal conditions and reduce the influx of warm, moist air.
While condensation on the outside of the bottle is generally harmless, it might cause minor inconveniences like wet surfaces or difficulty gripping the bottle.