Fermented skate is one of the most popular foods in South Korea, as well as one of the stinkiest. The dish, called "hongeo," is described even by its fans as smelling distinctly of outhouse. Joe McPherson, American founder of the Korean food blog ZenKimchi, has compared its consumption to "licking a urinal."
Photo credit: eggnara via flickr | CC BY 2.0.
A brief aside, for context: Skates are, to put it mildly, unusual animals. Like their look-alikes, rays, they belong to a subclass of cartilaginous fishes known as elasmobranchs. Sharks are elasmobranchs, too, so marine biologists sometimes refer to skates affectionately as "stepped on sharks." In 2011, researchers discovered that skates are some of the only vertebrates on Earth missing a chunk of genetic code, once thought to be indispensable, called the HoxC gene cluster. They have eversible jaws, and their undersides look like funny little faces. When they lay their fertilized eggs, they do so in a hard case referred to as a "mermaid's purse," which looks like this:
A Mermaid Purse via Wikimedia Commons | CC BY 3.0.
So yeah. Weird fishes, those skates. Which we suppose makes it a little less surprising to learn that, when fermented and served as sashimi, they taste and smell pretty much exactly like an outdoor toilet.
The dish's putrid tang can be traced to the ammonia that skates exude from their flesh. These fumes are so strong, Choe Sang-Hun reports in The New York Times, they're known for causing people's mouths to peel. This minor detail has not prevented the fish from amassing a considerable following throughout South Korea's southern islands. Residents of Heuksan Island, where hongeo trade has long been essential to the local economy, tell Sang-Hun that the dish's success can be attributed in large part to – surprise! – the skate's aggressively unusual biology:
In the days before refrigeration, the fishermen's forebears learned that hongeo was the only fish they could ship from to the mainland 60 miles away without salting. The hongeo lacks a bladder and excretes uric acid through its skin. As it ferments, it oozes ammonia that keeps it from going bad.
"Hongeo can't pee, and that's where the miracle begins," said Kim Young-chang, 77, the owner of a hongeo restaurant [on Heuksan Island].
More on this "miraculous" delicacy at the NYT.