Is Frozen Fish Sushi-Grade?

Any recipe that has raw fish as its primary ingredient can be intimidating. You may have to go in search of sushi-grade fish, and then you might wonder if it's okay to use frozen. This can all have you scratching your head as to what exactly "sushi grade" even means. Technically, the term doesn't mean much, except that the fish is generally considered safe to eat raw. 

The USDA doesn't regulate the term "sushi grade," so there are no official rules for putting that label on a pack of raw fish. It's more of a marketing phrase used by fishmongers. The term has gained traction with the increasing popularity of traditional Japanese cuisine, but what it essentially signals is that the fish has been handled properly from the moment it was caught to the time you purchased it.

If you're wondering whether your frozen fish can be considered sushi grade, flip the question to grasp it better: Does sushi-grade fish need to be frozen? The short answer is yes, in most cases. Freezing fish not only helps preserve its flavor and nutrients but also kills potential parasites when it's frozen to -31 degrees Fahrenheit for at least 15 hours. So maintaining a cold chain is sacrosanct for the fish to be sushi grade. The FDA has specific guidelines for freezing fish meant for raw consumption, making it almost mandatory. But this doesn't mean all frozen fish is sushi grade.

For sushi, there's an inclination for fish that pair well with ingredients like rice, seaweed, and wasabi. Tuna and salmon check that box. Their clean and mild flavors make them ideal for eating raw, which is why they're also the most common in sashimi. Tuna, however, stands out for another reason: It's less susceptible to parasites even when it hasn't been frozen. This makes it the top choice in raw dishes beyond sushi, too, including tuna tartare (which you can make with frozen tuna).

Salmon, whether wild or farmed, must be frozen soon after being harvested. While the risk of parasites may be lower than in other species, it's still high enough to make freezing essential. Fish like cod or flounder, on the other hand, are much more prone to parasites, so even if they are frozen, they aren't ideal for raw consumption.

Once you've decided on the right kind of sushi-grade frozen fish to buy, look for a store that's properly equipped to handle sushi-grade seafood. Some specialty markets across the U.S. use flash freezers or shock freezers that bring the temperature down to -30 degrees Fahrenheit much quicker than your freezer at home can. These ultra-low and fast freezing methods help eliminate the risk of parasites and foodborne illness while preserving the fish's authentic flavor, making it taste as good as fresh. Just be sure to properly defrost your frozen fish once you get it home.