Coffee sniffers

Two standing men in uniform are seen inspecting a group of three women sitting around a table with one men inspecting the coffee pot. One of the women is hiding a pot under the table. A maid is standing nearby looking at the scene.
Die Kaffeeriecher, based on a painting by L. Katzenstein

The coffee sniffers (German Kaffeeriecher or Kaffeeschnüffler) were a group of about 400 war invalids whose job was to literally sniff out smuggled coffee being roasted or consumed. They were employed between 1781 and 1787 by decree of Frederick the Great during a period when Prussia imposed a high luxury tax on coffee. Prussia did this to keep money in the country, and to encourage domestically-produced alternatives such as beer and chicory.

Besides Prussia, the Landgraviate of Hesse-Kassel also employed coffee sniffers to enforce a ban of coffee instituted in 1766 and tightened in 1774 by Frederick II, Landgrave of Hesse-Kassel.