In the 1980s, you couldn’t turn on your rabbit-eared TV without encountering one of those Folgers commercials that now seem delightfully campy. The setting shifted, but the premise was always the same: Unsuspecting coffee drinkers at upscale restaurants had their usual fine-pedigreed brew swapped for a cup made with instant crystals. A “hidden camera” revealed them raving about the drink and registering surprise when told about the secret switcheroo.