Is the freshest fish always best? Common wisdom says yes. Seafood expert Jon Rowley says no. He says the perfect time to cook and eat a fish is as much as five to six days after it died. Can he be serious?
"Some of the best chefs in the country," he says, "have difficulty getting their minds around the idea that fish can be too fresh or that a fish coming out of rigor mortis five or six days after harvest (in ice, of course) can be far better eating than a fish less than one day out of the water. To my knowledge, this phenomenon has never been written about, even though an understanding of how a fish goes through rigor is essential to achieving the best flavor, texture and mouth feel of any fish."
About three hours after a fish dies, says Rowley, it goes into rigor mortis--the progressive muscle stiffening that results from a coagulation of muscle protein. How long this state lasts depends on how it was killed and how it was treated after death. A fish that is killed properly and immediately iced down will stay in rigor mortis up to five or six days; an improperly killed fish will stay in rigor mortis only a few hours. If a freshly caught fish is going to be frozen, says Rowley, it should be done quickly, before it goes into rigor mortis.
Rowley's been talking about his rigor mortis theory for some time, but until now he has never actually put it to the test. In The Times Test Kitchen, Rowley wears the nervous, excited look of a kid attempting his first chemistry experiment.
In front of him are three pieces of catfish: one purchased as a fillet from a supermarket fish case, a second Rowley cut himself from a whole catfish killed within 24 hours; and a third fillet Rowley just cut from a whole fish purchased live within the hour from a live fish tank in a Chinatown supermarket.
All three fillets are brushed with butter and broiled at the same time, in the same pan.
The first fish, a bit pinkish raw, acquires a slightly grainy texture when cooked. The flavor is muddy to the point of tasting slightly moldy. ("That's a fish from Mississippi," says Rowley. "It tastes different from the catfish that are farmed in California.")
The second is slightly opaque and very white. The texture, when cooked, is very pleasant and the flavor clean and delicious.
The freshest, when filleted, is clear and slightly green. On cooking it seizes and scrunches up into a sort of ball. The texture is both mushy and grainy and the flesh is almost tasteless. It is not delicious.
The best of the three is clearly the whole catfish that had just come out of rigor mortis when purchased. Rowley has indisputably proved his point.
Which leaves us wondering why live fish is so popular in Chinese restaurants. We ask Ken Hom, one of the most respected Chinese chefs in America. "With really fresh fish," he says, "nothing is ever done to it except steaming. And it must be steamed very slowly, so it doesn't seize up. If you go into a restaurant and order fresh fish and say you want it fried, the Chinese will say, 'Are you nuts?' But if you steam it, then you can really taste the freshness and the flesh won't seize up."
"Yes," replies Rowley, "but it will still be mushy."