I have this button on a few jars around the house like jam jars, they are always glass. Why does the “button” pop once and never again?
In: Physics
It’s all about air pressure during the jarring process. Normally products jarred are pasteurized to kill bacteria. When the jar is heated and then cooled, the air pressure inside basically pulls that button. When you twist the top, you release the pressure and the button pops. Does this help?
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