Fans of Coors Light beer may have been wondering how the company's marketing team snagged thermochemistry for their latest sales gimmick. Well, renowned chemistry blogger Adam Aznam has the low down on the cool down. Coors Light bottles are printed with a thermochromic ink in the form of a leuco dye, he explains, these have a colorless form and a colored form. At too-warm-to-drink temperatures, the dye is colorless, but cool to refrigerator temperature and apparently, "the Rockies turn blue," indicating that the beer is at the right temperature to drink (in moderation, of course).
Thermochromics for beer drinkers