More and more, Californians want to know about the origins of their food these days.
For example, we have an initiative, Proposition 37, whose passage would require that products with genetically modified organisms be so labeled in the marketplace. Also, our farmers markets succeed in part because people can meet the growers face to face.
If we were in Japan, and we bought a piece of ahi tuna in a store, the provenance of that fish would be available to you on the spot: who caught it, how, where, when and more. Here, not so much. There is a bit of labeling about line caught and waters of origin, but often there is nothing.
After writing about fish in my most recent column, I thought it might be instructive to dive deep, as it were, on a specific fish. I found one at Zen Toro, the Japanese bistro and sushi bar hidden within Mansion Square on E Street in downtown Davis.
Masa Nishiyama, who operates Zen Toro with his wife, Masako, had a back-side loin of yellow fin tuna from the Gulf of Mexico. The next day it would be served to customers. But where had it originated, and how was it being handled from step to step until the moment customers enjoy it?
The loin weighed almost 14 pounds, indicating a fish that had been in the 80- to 90-pound range. The bar-coded label, from True World Foods in San Leandro, specified that it had been line-caught in the Gulf of Mexico about a week earlier. Masa knew the fisherman was a small operator who returned to port in Louisiana every few days with his catch.
Yellow fin tuna, he explained, is usually gutted right on the boat. Without gutting, the flesh of the fish would contract and be tighter a day later, plus there’s a taste issue. This fish was kept on ice because the fisherman was returning to port quickly; the big operators, out at sea a long time, may freeze them.
In Louisiana, the flesh near the tail was surely scraped to determine the fattiness of the tuna, Masa explained. If it’s fatty, it must be sold rather quickly. Exposure to air creates an unappealing hue on ahi if it’s fatty. Masa said it’s akin to the way an avocado darkens if left exposed.
I recalled that fatty tuna was held in low regard in Japan a half century ago — where had I read this? — and Masa confirmed it. “Nobody eats the fatty tuna,” he said with amusement. Now it’s prized, and Americans pay more for it.
Our tuna had a beautiful dark red color, a sign it was AAA quality, the highest, as indicated on the label. I called a fish wholesaler, Nguyen Pham, who explained that AAA and AA (about a $1 apart in the wholesale price) is the standard at good sushi restaurants. Sushi buffets and all-you-can-eat places typically serve either fresh single-A yellow fin, which is about $2 less than AA, or frozen carbon-treated fish. In other words, it’s gassed with carbon for color. It’s a telltale pink in a sushi bar or supermarket, where the pink color lingers for days.
“The yellow fin price has dropped about 80 cents in just the past week,” Nguyen said. Why? Volatility in Chinese demand. “China is driving the whole seafood world,” he explained. He said a lot of last year’s West Coast Dungeness crab harvest was scooped up by the Chinese market, which offered higher prices — in some cases wiring money directly to West Coast fishermen.
Masa quickly cut the loin into a number of large pieces. The dark bloodlines were discarded, as they taste “off” on a yellow fin. The less-than-choice flesh, slightly tougher, is consigned to spicy tuna, which is heavily chopped.
The sections were wrapped in a paper towel, because they would exude a slight amount of blood for the next 24 hours. Without the paper towel, the yellow fin would be fishier on the palate. Firm sections of a loin also are swathed in clear wrap at this point, but flesh from a softer tuna doesn’t get the wrap from Masa, who is very particular about his fish. The goal is to entice firmness for use the next day. He stashes the sections into the coldest part of the refrigerator.
The source for yellow fin will regularly change, Masa said, with AAA yellow fin coming to market from the Marshall Islands, Philippines and Indian Ocean. It truly is a global market — the antithesis of farm to table. Yet most of us, I dare say, dismiss local when it comes to fish from the sea, switching to the issue of sustainability as a point of concern.
By now, of course, that particular tuna has disappeared into the mouths of dozens of Davis residents in the form of nigiri sushi or sashimi. Another ahi has taken its place, and yet another will tomorrow.
Tuna steaks at home
Begin with dark-colored, fresh tuna steaks for best results, but the carbon-treated, pinker steaks may be far less costly, causing a value judgment: taste versus cost.
Rub all sides liberally with sesame oil. Put into a frying pan over medium-low (pre-heated). Let it sizzle for 12 seconds; alternatively, whisper the Pledge of Allegiance. Turn and repeat the pledge. Now grab with tongs and hold one way and another to sear the edges.
While the interior fresh tuna muscle does not have any pathogens, consider that the tuna you bought has not been destined for a sushi restaurant and has been sitting exposed on sale, plus any handling. I remember a discussion with now-retired Yolo County Health Officer Bette Hinton about potential pathogens on raw fish surfaces, so it’s a routine step for good home-kitchen food preparation.
Now the ahi can be sliced thick for serving. For dipping, many like soy sauce with wasabi, but there are numerous alternatives. Look online.
— Dan Kennedy, a Davis resident, has a long history with the bounty of gardens and small farms. Reach him at firstname.lastname@example.org