Bad, yet still pretty good, American cheese refuses to expire—and not just because of all the preservatives. American cheese—pasteurized, processed, and super-melty—is, for better or worse, arguably the 20th century’s most iconic food product. And yes, “pasteurized, processed cheese food” is what federal regulators call it instead of “cheese.” It is a paradox embraced shamelessly by some of the most elite food names around.