Learn what can cause a foggy buildup inside your sealed plastic jars. Discover the role of temperature changes and moisture.
1 Answer
Fog inside tightly sealed plastic jars is primarily caused by condensation of moisture that evaporates from the contents of the jar, especially if the contents have a high water content or the temperature fluctuates. The moisture condenses on the cooler inner surfaces of the jar.
Detailed Explanation:
The process behind fog formation in sealed plastic jars is relatively simple. First, consider that most organic materials, and even some inorganic ones, contain some amount of water. Even seemingly dry goods can release moisture over time. This moisture evaporates into the air inside the jar.When the temperature inside the jar fluctuates, the air's ability to hold moisture changes. As the temperature drops, the air becomes saturated with water vapor. When the air reaches its dew point (the temperature at which condensation begins), the excess moisture turns back into liquid water.Because the jar is tightly sealed, the moisture cannot escape. Instead, it condenses on the coolest surfaces inside the jar, which are usually the inner walls. This condensation appears as fog or small water droplets. The amount of fog depends on the amount of moisture released by the contents, the temperature difference between the contents and the jar's surface, and the jar's size. Higher humidity inside the jar will lead to more fogging.
Pro Tip:
To minimize fogging, ensure the contents are as dry as possible before sealing the jar. You can also add a desiccant packet (like silica gel) to absorb excess moisture.