How To Make Your Sushi Safe To Eat

Sushi is a Japanese dish that has spread to other parts of the world, where it continues to remain a popular food. Because sushi includes raw fish, many people avoid eating it in fear of contamination, parasites, and foodborne illness. Fortunately, you can enjoy sushi without worry, as long as you prepare and store your sushi correctly.

To make your sushi safe to eat, use only sushi-grade fish. Acidify your rice to prevent bacterial growth, and choose quality seaweed for wrapping your sushi. When preparing sushi, use clean utensils and cutting boards. Store the sushi in the refrigerator once prepared.

Indulging in sushi shouldn’t be a stressful or frightening experience. Throughout this article, you’ll learn the following:

  • Risks of eating sushi
  • How to choose fish for your sushi
  • Proper rice preparation
  • Precautions when making sushi
  • Sushi storage tips
  • How long you can safely store sushi
  • When to avoid sushi

The Risks of Eating Sushi

When it comes to raw fish, there are several hazards to consider. These hazards include:


Spoilage, while not necessarily dangerous, can cause fish to smell unpleasant and feel slimy. However, spoiled fish can signal prior mishandling of the seafood or indicate that it’s no longer fresh. Improperly handled fish is more likely to contain dangerous pathogens.

Pathogenic Bacteria

Pathogenic bacteria are a cause of foodborne illness in humans. Fish, when consumed raw, is at a higher risk of containing bacteria than properly cooked fish. Since fish prepared for sushi is consumed raw, proper handling and processing of fish are imperative. Only purchase fish from a qualified fishmonger or market.


Parasites pose yet another risk for sushi lovers. Anisakis, also known as the herring worm, is a common parasite in raw fish. Fortunately, sushi chefs and seafood processors know to watch out for this worm and toss infected flesh. Again, a reputable fishmonger or market is necessary for obtaining parasite-free fish. They will typically freeze fish beforehand to kill any parasites that they might miss.

We’ll discuss this more in-depth in the next section.

Mercury & Other Heavy Metals

Other heavy metals, such as mercury, are often found in raw fish and shellfish. Mercury levels depend on the quality of the sushi, with sashimi typically containing higher amounts. Tuna rolls usually have the least. In moderation, this shouldn’t pose much of a problem.

Choose Sushi-Grade Fish & Check for Freshness

Choosing a reputable retailer for your fish is a must. You’ll want to choose sushi-grade fish to ensure safe, quality sushi. While the “sushi-grade” standard isn’t officially recognized, many retailers will only place this label on quality fish intended for raw consumption. Sushi-grade fish is more expensive.

When choosing fish for your sushi, frozen fish is best. Low temperatures slow the growth of bacteria and kill parasites. Fish should be flash-frozen by a seafood processor. Fresh fish may be frozen at home at -4 degrees Fahrenheit (-20 degrees Celsius) for a week before use.

When ingredient shopping for your sushi, ensure that you’re buying safe fish using the guidelines below:

  • Smell the fish. Fish should have a fresh, pleasant aroma. If it smells fishy, sour, or rancid, it is likely spoiled.
  • Examine the eyes and flesh. When purchasing whole fish, the eyes should be clear and shiny. Don’t purchase fish with dry, crusty, or slimy eyes. The meat should be firm, and the gills should be pink or red. There should be no discoloration.
  • Press on the fish. Fish fillets should be firm with red veins. When pressing on the fish, the flesh should “bounce” back.
  • Look for time indicators. Some seafood manufacturers will include temperature indicators on the packaging. These indicators will show whether the food remained in storage at the proper temperature.
  • Avoid certain fish. Some fresh fish, including trout, yellow perch, and pike, shouldn’t be consumed raw and aren’t good options for sushi. You must cook these fish thoroughly before consumption.

Frozen fish may or may not share the above characteristics but should still smell mild, not fishy or sour.

Acidify Your Rice With Vinegar & Sugar

People that have developed an illness after consuming sushi often blame the fish. In reality, improperly prepared rice is just as, if not more likely, to cause illness. Rice contains bacteria spores that can survive the cooking process. Within an hour of preparation, rice needs to be cooled down in the refrigerator to avoid spore germination.

Acidifying the rice is also recommended. For sushi, prepare rice according to the package instructions. To acidify the rice, add vinegar and sugar. Acidic rice has a low pH which prevents pathogens from growing. When you adequately prepare rice for sushi, it isn’t dangerous, and you can store it in the refrigerator for up to five days.

Buy Seaweed from a Trusted Retailer

Seaweed is high in many essential vitamins and nutrients. This superfood is a staple in most sushi recipes, but some risks are associated with seaweed consumption.

One seaweed risk is exposure to heavy metals. When seaweed is grown in unacceptable conditions, it can absorb heavy metals from the surrounding environment. Always buy seaweed from a trusted retailer.

Another health concern with seaweed is iodine. Seaweed generally contains high amounts of iodine, which can cause adverse health effects when eaten often. When consumed in moderation, however, seaweed is not considered a health risk. In fact, experts agree that seaweed provides many health benefits.

If you’re well-versed in what to look for and what to avoid, you may also forage for seaweed. The water surrounding the seaweed should be clean and clear. Areas of contamination, such as areas near sewage systems or industrial pollution, should be avoided. Never use freshwater seaweed, as it can be toxic.

Take Precautions When Preparing Sushi

Making sushi at home is possible, but you must know what you’re doing to avoid any cross-contamination.

Here are some precautions that you need to take when preparing sushi:

  • Use clean, stainless steel utensils. Wooden utensils contain many striations, or grooves, that are difficult to wash and can lead to bacterial growth.
  • Wash all utensils, bowls, plates, cutting boards, and countertops. After preparing sushi, immediately wash everything in hot, soapy water.
  • Wash your hands. This step is a no-brainer. To prevent cross-contamination, keep your hands clean. You may also wear gloves, but you should still wash your hands before and after preparation.

By properly preparing your sushi, you can have peace of mind that your dish is safe to eat.

Wrap Sushi in Plastic Wrap & Refrigerate Immediately

Sushi preparation determines how long it will last. While not considered traditional sushi, a California roll prepared with cooked fish will store longer than rolls made with raw fish.

Store all sushi within 30 minutes after preparation. Roll the sushi tightly in plastic wrap and then place it in an airtight container. Place the container in the refrigerator to ensure it stays at the proper temperature. Leaving your sushi at room temperature for too long can lead to foodborne illness.

How Long After Sushi Is Made Can You Eat It?

Sushi made with raw fish is best when eaten immediately after preparation. However, it may be stored in the refrigerator, tightly wrapped, for up to 24 hours. While storing sushi in the fridge for a day may alter the general texture and flavor, it is unlikely to cause health issues. You can store cooked sushi for up to three days after preparation.

Consuming sushi made with raw fish more than 24 hours after its preparation isn’t a good idea. The longer raw fish is stored, the more susceptible it becomes to bacterial growth. Additionally, if your sushi tastes or smells fishy, sour, or like ammonia, throw it away.

Know When To Avoid Sushi

Because eating sushi comes with potential health risks, some people are better off avoiding it altogether. Pregnant women, young children, and immunocompromised individuals may avoid sushi due to the mercury, parasitic, and bacterial infection risk. Even when sushi undergoes proper preparation, the risk remains.


Sushi, a nutrient-dense dish, has been consumed for thousands of years in different parts of East Asia. There are many different variations, but it’s generally prepared the same: raw fish, rice, and seaweed.

There are potential health risks associated with eating sushi, but enjoying it doesn’t have to be a complicated or frightening experience. By understanding the risks and knowing how to safely prepare and store your sushi, you can indulge in this delicacy with peace of mind.


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