This idea, while an awesome use of physics, has a problem -even in the cleanest of brewing processes, the brewed beverage continues to go through chemical changes as it sits. Preserving their idea of a "perfect" temperature in order to preserve the coffee longer is inherently flawed, as it will begin to taste bad after a certain point no matter what. All coffee is temporary; do yourself a favor and brew more. Top-notch shops aren't dumping their airpots after 45 minutes because the coffee has cooled down too much.