Can You Freeze Sashimi? Everything You Need to Know

Going out to eat in the United States back in the 1960s would have been an extremely different experience than it is today. Even the recipes in cookbooks would have been entirely different.

Whilst some recipes are seemingly timeless like stews, soups, or various casseroles, there were some dishes like desserts and salads encased in gelatin or meatballs with grape jelly that seem to have been left in the past – which I am totally fine with by the way. I’ve never been the biggest fan of encasing food in gelatin after all. 

However, aside from gelatin, jelly, and t.v. dinners, the 1960s is also when something much more exotic (at the time, that is) entered the mainstream dining-out culture of the era – sushi. This is the time period where the “sushi bar” rose to popularity and more people experienced eating sushi and sashimi for the first time. 

Nowadays, eating sashimi and sushi is cheaper than it was 60 years ago, so it’s much more likely that you’ll be eating it – perhaps even for the first time.

But, what happens if you order or you make too much sashimi? Can you freeze sashimi? Yes and no, it depends on if it’s already prepared or not. Read on to learn more.

What is Sashimi?

While it’s often categorized as sushi, sashimi is not sushi.

Sushi is an umbrella term that refers to the various types of prepared dishes that include vinegared rice (prepared sushi rice) and most commonly a thin slice of fish on top.

However, there are various types and forms of sushi like chirashizushi (scattered sushi), nigirizushi (sushi rice with fish and a thin strip of seaweed around it), and makizushi (rolled sushi). The sushi that we’re most familiar with today (vinegared rice with a thin slice of fish on top) originated from modern-day Tokyo (Edo at the time) between 1603 and 1868. 

Sashimi, on the other hand, is fresh fish that’s been thinly sliced and it’s often eaten with soy sauce and is always served on its own. The word sashimi, which translates as “pierced body”, dates back to the Muromachi period (1336-1573) and it’s also thought that the dish originated during this same time period. 

Sashimi Grade Fish vs Raw Fish

There is no legal distinction between all raw fish and what many restaurants brand as “sashimi-grade” raw fish. This is because there’s no concrete definition of sashimi-grade fish since it’s an unregulated term (unlike regulated terms when it comes to poultry or beef, for example). However, it’s often used in good faith to signify that the fish is the freshest and of the highest quality and treated with extra care to limit the risk of food-borne illnesses.

So, while you shouldn’t put your full faith in fish that’s labeled as sashimi-grade, as long as the restaurant follows FDA guidelines and has a good rating, then you should be fine. Most respected sushi chefs will generally have faith in their product. 

Sashimi is Typically Frozen

Speaking of guidelines, though, due to FDA guidelines and general fishing best practices, it’s most likely that much of the sashimi that you’ve eaten has been frozen.

This is because the FDA has stated that any wild fish (except tuna species) that’s to be eaten raw should be frozen at -31 degrees Fahrenheit for up to 15 hours or -4 degrees Fahrenheit for 7 days to kill any parasites. And in the EU, the restrictions are firmer. Since 2006, any fish that’s to be served in sushi or sashimi must be frozen for a minimum of 24 hours at a temperature of at least -4 degrees Fahrenheit.  

There are some people that are angry at the notion of freezing the fish before eating it raw as they claim that the freezing of the water particles in the meat of the fish, harms the cell walls in the meat, thus making it less desirable.

However, with today’s modern freezing technology, that’s something we don’t really need to worry about. In fact, even a renowned sushi chef at Nobu, Shin Tsujimura, told the New York Times that it’s very unlikely that someone could tell the difference between fresh and frozen fish since even he couldn’t even tell. If that’s the case, I would rather have more peace of mind about my sashimi being free from parasites than worry about the fish being frozen. 

Can Prepared Sashimi Be Frozen?

Unfortunately, prepared sashimi shouldn’t be frozen.

As I’ve already mentioned, it’s already been frozen once, so, like most foods, it’s better to avoid freezing it again if possible.

While it most likely won’t be dangerous to eat, you’ll likely be very disappointed about the mushy fish you’ll have after you defrost it. So, it’s best to try to eat all of it while it’s freshly prepared, or you can also store it in the fridge as long as you treat it carefully. More on that later, though. 

Can You Freeze Leftover Sashimi?

No, you can’t (or shouldn’t) freeze leftover sashimi.

If sashimi has been prepared or has been served and is leftover, you should avoid freezing it in both cases.

Just because it may be safe to eat, you should avoid it because an additional freezing and thawing cycle will cause a lot of harm to the meat. And it will be even more noticeable since freezers at home aren’t powerful enough to quickly freeze the fish with minimal damage. 

How to Freeze Sashimi Grade Fish

However, just because you can’t freeze prepared sashimi doesn’t mean that you can’t freeze sashimi-grade fish.

In fact, if you plan on doing a sushi night at home with fresh fish, then you should definitely freeze it!

But, you can only freeze it if your freezer is powerful enough. While it doesn’t have to be powerful enough to get down to -31 degrees Fahrenheit, it needs to be able to drop to at least -4 degrees Fahrenheit. If not, then you can’t guarantee that the parasites will be properly killed and you’re taking a risk by eating it raw. 

If your freezer can reach the magic number of -4F, then you’re good to go. Here are the specific steps of freezing sashimi-grade fish:

Preparation

  • First, if it’s a full fish then you’ll need to descale, debone, and clean the fish.
  • Then, depending on the size of your fish, you may need to cut it into large steaks or fillets for freezing. However, by preparing the steaks first, you save time and effort later. For the best results, you should use a proper sashimi knife
  • (Optional) You can pre-treat your fish to help maintain the flavor and texture. You may pre-treat fatty fish, such as mackerel, trout, salmon, or tuna, by dipping it into a solution. 20 seconds with 1-quart cold water and 2 teaspoons of crystalline ascorbic acid. If you have a lean fish, such as flounder, cod, snapper, or most freshwater fish, brine it for 20 seconds in 1-quart cold water and 14 cups salt.

Freezing

  • Next, freeze the fish by laying it in a single layer in your freezer until it is solidly frozen, which should take around 30 minutes.
  • (Optional) You can make an ice glaze for even greater protection. Return your steak or fillet to the freezer after a quick dip in mildly salted water (1 tablespoon salt per quart of water). 
  • Finally, remove as much air as possible from your frozen steaks and fillets by placing them in a freezer-safe Ziploc bag or wrapping them individually in plastic wrap and placing them into a freezer-safe, airtight container.

How Long Can Sashimi Grade Fish Be Frozen?

Sashimi-grade fish can be frozen for up to 6 months. But consuming earlier is better. 

How to Store Sashimi After Preparing

After sashimi has been prepared you can still store it in the fridge, however, you should store it and eat it very quickly. To store it, simply pack the sashimi tightly in plastic wrap. Then place it into an airtight container. Generally, you should store it in the fridge within four hours and eat it within one day

How to Tell if Sashimi Has Gone Bad

Simply enough, just smell it. You can easily tell if sashimi has gone bad by the smell, it shouldn’t have a strong fishy smell. But it will often show signs too. The first sign that it’s bad, though, is by the smell, so make sure to avoid eating any sashimi that smells off in any way.