LITTLE KNOWN FACTS ABOUT VALVES.

So coffee bags have these ingenious 1-way "degassing" valves on them product of membranes that open up if the strain builds up within. That's why you are able to "awaken and odor the coffee" without having truly opening the bag. When air tries to force in from exterior, it flattens the membrane and seals the bag restricted. Thus far so very good, b