Updated: May 15, 2020
"How should we keep this Tai Snapper in the fridge? “Looking at the whole fish, I asked Toru, the executive chef at Yoshida Sushi in Hollywood.
"I think we should cut the head off, store the whole thing, tightly wrapped in plastic," Toru answered.
Then, Take-san walked in from the back employee entrance to the Sushi Bar.
"Ohayo Gozaimasu," He greeted us.
"Ohayo Gozaimasu," we greeted back to him. Just before he was about to enter the locker room, he looked back to us and said, "What are you all discussing? You look so serious."
"We are wondering what's the best way to keep the Tai, fresh in the refrigerator," I said.
"I see," Take-san nodded, as he put his Sushi Chef uniform.
"Should we fillet it or store it as a whole fish?" I asked.
"Well, for Tai, you should fillet it, then wrap it in plastic and keep in the fridge," Take-san said.
"Same with Hirame and other white fish too," Take-san told us.
"Really?" I could not believe what he said. "Would it be better not to fillet it because of discoloring as it happens to Tuna?"
"I know. It's hard to believe, right? I don't know exactly why, but from my experience, for white fish, it works better if you fillet it," Take-san said.
I was thinking I should wrap it in the paper towel first, as we do with Tuna to prevent it from discoloring. They even sell paper designed to keep the red color of tuna when you wrap it in them.
"It's not like Tuna?" I asked Take-san.
"No, Tuna you want to wrap first in paper and then plastic wrap. Not white fish."
I remembered another Sushi Chef telling me about Ama-Ebi, Sweet Shrimp. He said Sweet Shrimp starts to taste better after two to three days in the fridge, compared to the fresh one. When fresh, the texture is nice and plump, like cooked shrimp, but the umami is less. When aged a couple of days, Sweet Shrimp indeed develops sweeter umami flavor, the chef told me. The tradeoff is the texture goes down as the time passes. The flesh gets softer, which affects how we sense the overall taste.
I had no idea about fish aging even after I became a Sushi Chef until some chefs told me about it. I always thought the fresher the fish, the better it is and tastes but I learned that is not always the case.
I learned from Paul Johnson, the owner of Monterey Fish Market in San Francisco that Salmon is at its prime when it's five days since it is caught. Tuna like Yellowfin, Big eye and Bluefin take anywhere from five days to up to fourteen days to have nice savory taste. It is the same concept as aging beef to increase amino acid, glutamine or Umami in the meat.
At one Sushi Restaurant in LA, I remember having "live" halibut from fish supplier. It was dead when arrived at the restaurant, but the owner brought it back saying, it was live and fresh when picked it up. We fillet and sample some to see how it tasted. The "live" Halibut had almost no taste and very tough like rubber, not eatable at all. So we decided to let it sit and age, which Japanese call it "let it sleep." We kept it wrapped tightly in plastic, over ice in the commercial refrigerator. On the third day, we sampled it. The meat was a lot softer, but it still lacked in Umami. On the fifth day, it finally started to taste like Halibut we used to know; sweet umami flavor and tender meat. Now the halibut was servable, we made Sashimi and Nigiri, but never told our customers about aging, thinking, it would confuse them.
I later watched a documentary, Jiro Dreams of Sushi, and learned Jiro's oldest son talks about them aging Bluefin tuna for up to two weeks to maximize its taste. It is Sushi chef's experience and skill to determine when is the best time to serve the fish he gets. As such, aging fish is a very important task for a sushi chef.
This is one of the reasons why I hesitate to answer a question by my customer, "What's fresh today?" or "When did you get this fish?" because fresh fish does not always taste the best and like Halibut's case, inedible.
Then, there is another issue about fresh fish. Many customers told me and asked me about some restaurants carrying live fish in a fish tank like spot prawns, crabs, lobsters and such. The question is, "Are they fresh and do they taste good because they are alive?"
The answer is usually "No."
Fish swim in the vast ocean and catch its own prey. Imagine, how you would feel to be placed in a small fish tank, not getting enough exercise, not getting enough food. Fish also experience stress from a change in their living environment. Considering these two factors, can we really say the fish in the fish tank is as healthy as when it was swimming in the ocean?
We tend to think automatically live fish is fresher and tastes better than the dead one. However, they are not always at their optimal health even though they are alive. It's usually the case those fish in a fish tank taste inferior to properly aged and stored "dead" fish.
So, the next time you go to the Sushi Bar, an excellent question to ask is, NOT "What's fresh today?" rather, perhaps ask "Which fish is at its prime today?"