In physics, this phenomenon is called the “Leidenfrost effect.” It can happen with any liquid, not just beer.

Normally, when you pour liquid into a hot pan, the droplets will sizzle and evaporate. But when you crank up the temperature so that the surface is significantly hotter than the liquid’s boiling point, the heat is so extreme that it boils the underside of the liquid immediately. The resulting vapor acts like a bed, protecting the liquid above it from touching the hot pan. The droplets will fuse together and evaporate very slowly.