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My understanding is that all "sushi-grade" fish is previously frozen. The freezing process is apparently necessary to kill/remove parasites in certain fish bree

My understanding is that all "sushi-grade" fish is previously frozen. The freezing process is apparently necessary to kill/remove parasites in certain fish breeds.

campground 9y ago
I believe this is only necessary for salmon. Because they spawn inland they host parasites whose life cycle includes terrestrial animals, like bears and humans.
- valuearb 9y ago
  Pretty sure all fish has parasites. I’ve read that chefs say all fish have worms.
- munificent 9y ago
  > whose life cycle includes terrestrial animals, like bears and humans. I don't think that's generally the case. As far as I know, the main salmon parasites that we care about are Anisakis (nematodes) and Diphyllobothrium (tapeworms). The former is much more common than the latter, especially in the US where as far as I know broad tapeworm has only recently been detected in a small fraction of Alaskan salmon. Anisakis has no terrestrial hosts. Its lifecycle is crustacean -> fish -> aquatic mammal (whales, dolphins, seals) -> repeat. Humans and other land mammals are the host of Diphyllobothrium, but, again, I don't think that's very common. From what I've read, most of the need to freeze salmon comes from wanting to deal with roundworms.
- pvaldes 9y ago
  Can host both types of parasites in fact. Killer whales and marine birds are another typical predators.
raspasov 9y ago
I recently learned that “sushi-grade” is just a marketing term that has no meaning beyond simply “good grade”. It’s most often used by restaurants themselves. It’s not regulated or oficially defined in any way.
munificent 9y ago
This is true for some but not all species. Most fishmongers will not recommend eating salmon raw unless it has been deep frozen (and not just frozen in a typical residential freezer, which doesn't get cold enough), but most consider eating raw never-frozen tuna to be fine. As with most things in life, it's really a question of risk and trade-offs. Parasites are rare enough in tuna that they are below the risk threshold for most people. Salmon less so, though it depends on where you get it and how much you trust them. The broad guideline is that deep, open water, fast-moving fish have a lower parasite load than fish who live closer to shore, closer to the bottom, and/or don't move as fast. Thus, tuna is pretty safe. But you're gonna want to cook an eel or a catfish before you stick it in your mouth. One of the things I find fascinating about sushi but try not to think about too much, is that the clear implication is that all of the needed-to-be-frozen sushi I have eaten probably did have some parasites in it. I just ate dead parasites, which I admit is better than eating live ones. Safe, but still kind of gross.
bogomipz 9y ago
There's actually no such thing as "sushi-grade" fish. There is no standard or regulation that designates fish as "sushi-grade." It's a popular misconception.
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- evincarofautumn 9y ago
  I always thought it was a marketing term, where a certain store is willing to say “we’re confident that this can be eaten raw” and not some legal or regulatory standard of quality or freshness—that is, I thought the idea that it’s a popular misconception was itself a popular misconception. Moreover, I’ve even heard it used to describe simply “species of fish that are commonly considered safe to eat raw”.
dragonwriter 9y ago
The article goes into some detail about the circumstances in which this is and isn't true (it's true for some fish from sources.)
Finnucane 9y ago
I think here in Massachusetts, at least, there is regulation to the effect that fish sold to be served raw _must_ be frozen to kill parasites. Possibly it is species-dependent, but I would make a guess that it is not. PS: turns out it is somewhat species dependent: http://www.mass.gov/eohhs/docs/dph/environmental/foodsafety/retail/sushi-guide.pdf http://www.mass.gov/eohhs/docs/dph/environmental/foodsafety/...
adrr 9y ago
Some of the poke places in LA use fresh tuna that was flown in from Hawaii. I think even the Costco poke is fresh. For those not familiar with poke, its a raw tuna , soy sauce and seaweed dish. You can remove parasites by sight easily.
- fencepost 9y ago
  > You can remove parasites by sight easily. I'd rephrase that as being able to spot fully grown parasites easily, but parasites don't always come fully mature.
MisterBastahrd 9y ago
A little off topic, but virtually all cigars imported into the US are frozen as well, usually by the distributors (there are a few companies who manage their own distribution who do not... like My Father / Tatuaje). This is to kill the tobacco beetle eggs that may be on the leaf. The exporters from Cuba also freeze their cigars before sale, but the cigars sold on the island itself (either name brands or custom rolls) are not. These beetles can cause thousands of dollars worth of damage very quickly.

My understanding is that all "sushi-grade" fish is previously frozen. The freezing process is apparently necessary to kill/remove parasites in certain fish breeds.

campground 9y ago

I believe this is only necessary for salmon. Because they spawn inland they host parasites whose life cycle includes terrestrial animals, like bears and humans.

valuearb 9y ago
Pretty sure all fish has parasites. I’ve read that chefs say all fish have worms.
munificent 9y ago
> whose life cycle includes terrestrial animals, like bears and humans. I don't think that's generally the case. As far as I know, the main salmon parasites that we care about are Anisakis (nematodes) and Diphyllobothrium (tapeworms). The former is much more common than the latter, especially in the US where as far as I know broad tapeworm has only recently been detected in a small fraction of Alaskan salmon. Anisakis has no terrestrial hosts. Its lifecycle is crustacean -> fish -> aquatic mammal (whales, dolphins, seals) -> repeat. Humans and other land mammals are the host of Diphyllobothrium, but, again, I don't think that's very common. From what I've read, most of the need to freeze salmon comes from wanting to deal with roundworms.
pvaldes 9y ago
Can host both types of parasites in fact. Killer whales and marine birds are another typical predators.

raspasov 9y ago

I recently learned that “sushi-grade” is just a marketing term that has no meaning beyond simply “good grade”. It’s most often used by restaurants themselves. It’s not regulated or oficially defined in any way.

munificent 9y ago

This is true for some but not all species. Most fishmongers will not recommend eating salmon raw unless it has been deep frozen (and not just frozen in a typical residential freezer, which doesn't get cold enough), but most consider eating raw never-frozen tuna to be fine. As with most things in life, it's really a question of risk and trade-offs. Parasites are rare enough in tuna that they are below the risk threshold for most people. Salmon less so, though it depends on where you get it and how much you trust them. The broad guideline is that deep, open water, fast-moving fish have a lower parasite load than fish who live closer to shore, closer to the bottom, and/or don't move as fast. Thus, tuna is pretty safe. But you're gonna want to cook an eel or a catfish before you stick it in your mouth. One of the things I find fascinating about sushi but try not to think about too much, is that the clear implication is that all of the needed-to-be-frozen sushi I have eaten probably did have some parasites in it. I just ate dead parasites, which I admit is better than eating live ones. Safe, but still kind of gross.

bogomipz 9y ago

There's actually no such thing as "sushi-grade" fish. There is no standard or regulation that designates fish as "sushi-grade." It's a popular misconception.

deleted 9y ago
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deleted 9y ago
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evincarofautumn 9y ago
I always thought it was a marketing term, where a certain store is willing to say “we’re confident that this can be eaten raw” and not some legal or regulatory standard of quality or freshness—that is, I thought the idea that it’s a popular misconception was itself a popular misconception. Moreover, I’ve even heard it used to describe simply “species of fish that are commonly considered safe to eat raw”.

dragonwriter 9y ago

The article goes into some detail about the circumstances in which this is and isn't true (it's true for some fish from sources.)

Finnucane 9y ago

I think here in Massachusetts, at least, there is regulation to the effect that fish sold to be served raw _must_ be frozen to kill parasites. Possibly it is species-dependent, but I would make a guess that it is not. PS: turns out it is somewhat species dependent: http://www.mass.gov/eohhs/docs/dph/environmental/foodsafety/retail/sushi-guide.pdf http://www.mass.gov/eohhs/docs/dph/environmental/foodsafety/...

adrr 9y ago

Some of the poke places in LA use fresh tuna that was flown in from Hawaii. I think even the Costco poke is fresh. For those not familiar with poke, its a raw tuna , soy sauce and seaweed dish. You can remove parasites by sight easily.

fencepost 9y ago
> You can remove parasites by sight easily. I'd rephrase that as being able to spot fully grown parasites easily, but parasites don't always come fully mature.

MisterBastahrd 9y ago

A little off topic, but virtually all cigars imported into the US are frozen as well, usually by the distributors (there are a few companies who manage their own distribution who do not... like My Father / Tatuaje). This is to kill the tobacco beetle eggs that may be on the leaf. The exporters from Cuba also freeze their cigars before sale, but the cigars sold on the island itself (either name brands or custom rolls) are not. These beetles can cause thousands of dollars worth of damage very quickly.