Sometimes a picture’s all you need. Check it out below: The bottle on the right is at room temperature. The one on the left is straight out of the fridge. See the difference?

If you’ve ever added beer to the fridge alongside stuff that’s already been chilling for days, you know that feeling the outside of the bottle after just a few minutes in the cooler doesn’t work, as the glass gets cold much more quickly than the beer inside.

Solution: Coors figured out how to put temperature-sensitive ink on its labels. It starts turning blue, says Coors, when the beer inside hits 47 degrees and finishes the process finishes at 43 degrees. Thus, you know at a glance which one’s the cold one without having to open it up and potentially spoil an otherwise perfectly good beer.

Is it a gimmick or a great idea? Well, I’m already starting to wish all beer had this nifty ink on the labels. (Alas, what I was really hoping for in a “cold activated bottle” was one that would chill itself without the fridge. Darn.)