Almost Every Kind of Wild Fish Is Infected with Worms
MUNCHIES find out that Ever have a nice meal at a fancy restaurant, plop down $75 for a seafood dinner, then get home and open the container of leftovers to see worms wriggling out of your fillet? Maybe (hopefully) this has never happened to you. But the current commitment to local, wild, and unprocessed seafood may be making that more likely.
“I got sea bass and just looked at my leftovers and THEY ARE CRAWLING WITH WORMS ALIVE WORMS.” Even without the text in all all caps, it was clear from the midnight text my friend, a local food writer, was freaked out—freaked out enough that she called a medical hotline which recommended she go to the emergency room. The videos she sent me of the squirming, blood-red worms, three of them, were gross. No doubt.
This wasn’t from some shack serving black market bass plucked from a slough. This was a meal at one of Portland’s top restaurants listed in every major media’s “best of” edition. And the fish was purchased from one of Portland’s top fish purveyors selling to Portland’s most highly regarded restaurants.
“There are parasites in almost every kind of fish,” one of Portland’s top fish purveyors, who sold the infected fish and wishes to remain anonymous, told me. “What I provide is as fresh as can be. It comes straight from the ocean to the restaurant.”
“I don’t eat raw fish because of what I’ve seen,” admitted the fish purveyor, who sells to many of the city’s top restaurants. “I don’t eat sushi anymore.”
The worms—nematodes called ascarids—are relatives of hookworms, pinworms, and even trichina worms, the parasite responsible for trichinosis. They are killed by freezing at a temperature of -4 degrees Fahrenheit for at least seven days, or by heating to a temperature of 145 degrees for at least 15 seconds.
You’d think cooking would destroy the parasites. But destroying the nematodes at 145 degrees is like cooking a burger well-done. As Harold McGee explains in On Food and Cooking, “most fish shrink at 120 degrees and begin to become dry around 140 degrees.” He places the ideal cooked temperature for most fish at around 130 degrees, but notes that “some dense-fleshed fish, including tuna and salmon, are especially succulent at 120 degrees.” That’s far short of the temperatures needed to kill the worms. Perfectly cooked fish, like a perfectly cooked burger, means taking a risk.