Why Some Grocery Store Grapes Have a White Coating!!

You see that white powder on your grapes? Most people think it's dirt you need to scrub off. So you wash it, right? Turns out, that's the worst thing you can do for your fruit. That cloudy film isn't filth at all. It's nature's secret shield against mold and decay. And if you scrub it away, your grapes will go bad fast. So what is that stuff, really?