Bests & Worsts Reviews from Amazon

Like most people, I learned in high school that CO2 is an inert gas, so how could it damage coffee? A little research showed me that the valves on coffee bags are there to allow oxygen to escape and to prevent them from inflating like balloons, not to somehow protect them from CO2. Then a bit of googling led me to the website of a coffee expert who tried in vain for months to get Friis to tell him if they have any evidence that CO2 is harmful to coffee (since that's the whole basis of their pitch) and he got nothing but vague marketing replies. Google up Friis Coffee Review Randy Glass to read the whole sad tale.