8. Glass cases
“The glass doors in the freezer section are often so covered with dirty fingerprints that you have to open the doors just to see what’s inside,” Backe says.
While this is, of course, annoying, it can also be very unsanitary: “This means that the spread of germs from the door to the item you’re about to pick up is practically inevitable.” He also suggests that, if this is not the case and the doors look clean, that’s a pretty good indicator that the rest of the store is above average in terms of cleanliness.