Is Sushi Fish Frozen? Unpacking the Myths Around Frozen Fish

Assess Your Fish Market

The Lobster Place and Osakana aren’t like other fish markets; they treat their fish better than most places. But if you’re not sure if you can trust the offerings and claims of a fish market you happen to stumble upon, you don’t have to talk to the fishmonger (though it never hurts to get to know the people selling you food). Instead, you can use The Lobster Place as a kind of visual guide—it shows you how to safely handle fish and how to present it. Fish fillets are put on aluminum trays that are set in a lot of crushed ice that drains well. The fillets are arranged so that their flesh touches other fish flesh as little as possible. Whole fish are buried in ice, and each one is set up in a way that looks like it would swim through water. (This is done to account for how the insides settle because of gravity. Keeping a fish that swims upright keeps one side from getting squashed, which would lower the quality of the meat.) The fish cutting boards behind the counter are cleaned and sanitized often. This is where the staff cuts whole fish into fillets in front of the customers. Even though it may not smell like fish, the huge displays of fish never smell bad or fishy. Instead, the air has a clean, marine smell.

How Dangerous Are Parasites? Depends Who You Ask

Despite the FDAs blanket recommendations for the elimination of parasites, which is the main goal of its freezing guidelines, very few infections from eating raw fish have been documented in American medical literature. In the US, eating raw fish that hasnt been frozen is rare enough that the agencys “Bad Bug Book” uses Japan as a reference point, since the practice is far more prevalent there. But even in Japan, where freezing of fish meant for sashimi is not required, reported infection rates are vanishingly small compared to the total population. (For instance, the Bad Bug Book reports “more than 1,000 cases” of infection by anisakis worms, the most common parasite in marine fish, reported annually in Japan, but keep in mind thats out of a total population of ~127 million in 2015.)

Many infections are thought to go unreported because they don’t cause any symptoms. This means that the risk of infection may be higher than statistics show. On a less scientific level, worms—particularly parasitic worms—inhabit dark recesses of our collective imagination. The thought of eating a piece of fish that looks clean and tastes great could be infested with organisms that look like aliens is enough to make anyone nervous, even health officials who have all the necessary, reassuring information.

Haraguchi and Herron both say that in some cultures, fish has been served raw for a long time even though it has never been frozen. They were both fine with the idea of eating fish that way, though they do stress that the fish they sell for raw consumption has been frozen according to FDA rules. Of parasites, Haraguchi says, “Its natural. Parasites are as natural as seeing a ladybug in farmers market vegetables. Herron tells me, “I’ve done the same thing.” I tell him that I bought fluke at The Lobster Place, butchered it, and ate it raw at home. Im fine, youre fine. And everybody was doing that before these regulations came out, and everyone was okay. “.

There are some exceptions, though. Broad fish tapeworms can infect freshwater fish and some anadromous fish, which are fish that live in both fresh and salt water, like salmon. These are thought to be more dangerous than other parasitic worms. A lot of parasites can infect fish in the cod family, especially Atlantic cod but also Pacific cod, haddock, and pollack. Because of this, not many experts recommend eating these fish. Haraguchi says there’s another reason cod family fish shouldn’t be eaten raw: “The flesh has so much water in it that it doesn’t taste good.” “).

The parasites that infect most marine fish are nematodes, or roundworms, from the genus Anisakis. It’s best not to eat them, but common sense says that if you do, the stray live anisakid in your gut will at least make you feel bad—nausea and maybe even stomach pain, like when you get food poisoning.

Dr. Parasitologist Judy Sakanari from the Department of Pharmaceutical Chemistry at the University of California, San Francisco, thinks that this view doesn’t give anisakids enough credit for how dangerous they are. “Infection with these parasites can be very bad and can cause resection [surgery to remove part of an organ] of the intestine,” she says. Sakanari stresses that we need to know about the parasite’s life cycle in order to fully understand the risks.

All parasites seek to reach their end-host organisms. For tapeworms, these are bears and other mammals that eat fish. For anisakids, these are marine mammals like whales, seals, and dolphins. If everything goes as planned by the parasite gods, an end-host organism will eat fish that carry infectious worm larvae. But if those fish are caught in a trawler or on a line, the parasites can’t live their best life. The parasite larvae in the fish’s gut will try to get out as soon as its temperature reaches that of the end-host mammal. This will cause them to burrow into the fish’s flesh. One reason it’s best to keep fish that haven’t been gutted cold is that any parasite larvae that are in the gut will stay still as long as the temperature is low enough.

That impulse to find a more hospitable environment, Sakanari says, is what makes anisakids particularly worrisome for humans. The human body is sufficiently different from that of whales and elephant seals—typical anisakid end hosts—that it forces the worms to wander around inside of it. As they do so, they probe along the intestinal wall, trying to penetrate it and sometimes getting stuck in the process, which can necessitate resection. (Interestingly, because humans are a natural end host for tapeworms, Sakanari says that tapeworm infection, as disgusting as it might sound, would be preferable to larval anisakid infection. The pathologies associated with the adult fish tapeworm infection are by and large less severe, and can be treated with a simple anthelmintic.)

Sakanari says that preparations like ceviche, where fish are soaked in an acidic bath, don’t kill anisakids because they like living in places that are very acidic. A strong light is shined through thin fish fillets that are placed on a glass to find parasites that need to be removed. This method is not perfect either; Sakanari talks about an experiment in which she and her colleagues used this method to look at a piece of rockfish and found that it was free of parasites. Once the fish was done, they took it apart and looked at it closely. To their surprise, they had missed a few worms. Even experts can fail to completely deworm a fillet.

The end result is that temperature is the only real way to be sure that you’ve killed any parasites in the flesh. “Its best to properly freeze or cook the fish. Thats the bottom line,” Sakanari says. She says, “It depends on how much you love the dish.” Is it worth the risk to eat raw fish that hasn’t been properly frozen? “Eating anything raw that hasn’t been properly prepared or washed always comes with risks, so it’s up to consumers to know what those risks are and how to avoid getting sick.” “.

Can You Refreeze Fish for Sushi?

Can you eat frozen fish for sushi?

It is not advisable to use frozen fish for sushi at home unless labeled “sushi-grade” or “sashimi-grade”. This is because to be designated safe for raw consumption, the fish has to be frozen to at least -4°F, and most home refrigerator-freezers do not go that low. It’s the process of freezing the fish that makes them safe to be eaten raw.

Is sushi considered as healthy food?

Sushi is a healthier choice, but it depends on which variety of fish is used to make sushi. Fatty fishes like tuna and salmon adds much omega 3 fatty acids to the dish. Fish is high in protein and sushi is prepared with plant based proteins like tuna and other vegetables, so sushi is regarded as a high protein food. It also contain more vitamin D, B12, than other foods, provides a source of essential minerals like selenium, zinc and iodine, it is a good source of omega 3 fatty acids. Hence sushi is considered as a wholesome food with a store house of all the essential nutrients.

Can sushi be frozen?

It’s a safe bet that anything sold as “sushi-grade” has followed FDA guidelines for freezing, even if there is no legal mandate to do so. But at the exorbitant cost of most sushi-grade items, you might be better off just buying the sushi from a restaurant!

What’s the difference between a frozen fish and a sushi-style fish?

There’s more that goes into a sushi-style fish than the freeze. Exemplars are often wild-caught and immediately filleted. Some of the water content is removed, and the blocks are then deep frozen, often at a frigid -30 degrees Fahrenheit. Such expert-driven processing ensures not only the safest composition, but the optimal flavor, too.