LITTLE KNOWN FACTS ABOUT VALVES.

So coffee luggage have these ingenious one-way "degassing" valves on them crafted from membranes that open when the tension builds up inside of. This is why you'll be able to "wake up and scent the coffee" devoid of truly opening the bag. When air attempts to press in from outdoors, it flattens the membrane and seals the bag tight. To this point so