Why can't you hear whoosh sound when you open the jar of pickle or peanuts at the second time or can you hear the sound at the second time?

Answer 1

Jars of peanuts, pickles, spaghetti sauce and others, are vacuum sealed at the manufacturing plant. That means that all the air is sucked out of the jar at the moment that the lid is screwed on. This is done to prevent bacterial growth. the whoosh sound we hear is the outside air rushing back into the jar when we open it for the first time. When we close the jar, there is always some air that stays trapped in the empty space under the lid. Since air is already present in the jar when we open it again, no air needs to rush in and no whoosh sound is produced.