Answer: Pistachio Nuts

If you’re a geek of a certain vintage, you may recall that pistachio nuts at your local market used to be a vibrant red in color (and sometimes would even leave red stains on your hands and mouth when you ate them). Yet today, you’ll rarely find red pistachios in the produce section—they almost universally have a very natural beige color, without a Christmas hue to be found. Where did all the red pistachios go?

Historically, the bulk of pistachios came from the Middle East where they were harvested using traditional methods. These methods left a harmless (but unappealing) discoloration on the shells of the pistachio nuts, so they were dyed red to mask the discoloration. Later, when other regions (like the U.S. state of California) entered the pistachio market, mechanical harvesting methods replaced the traditional harvesting methods. Mechanical harvesting did not discolor the shell and the need for the dye vanished.