03 — Physics
Why your coffee goes cold — and why this one doesn't
Coffee loses heat four ways: evaporation from the surface, radiation and convection from the walls, and conduction into the cold mass of the mug itself. The first pour into a room-temperature mug can shed several degrees to the ceramic in the first minute. The highest-leverage fix costs nothing — thirty seconds of hot tap water in the mug before the coffee goes in.
Geometry does quiet work too. The Daily's mouth is deliberately narrower than the diner-cup flare, exposing less surface to evaporation, the dominant cooling channel of an uncovered drink. A tall-ish, narrow-ish mug keeps coffee warmer than a wide shallow one of identical volume. Every curve on this mug is that sentence, applied.
Preheated, the thick stoneware walls flip from enemy to ally: a heat reservoir working in your favor. The full stack — preheat, thick stoneware, narrow mouth — keeps a cup drinkably warm for the better part of an hour with zero electronics. The warming-coaster industry is mostly selling a solution to an unpreheated mug.