Step 2: Soak two kitchen towels in water, wring out the excess, and lay one towel flat on a plate. Place the sushi on the towel, then cover it with the second damp towel. Refrigerate it after wrapping it in plastic wrap. This will prevent the rice from drying out and becoming stiff, albeit at the expense of the nori’s texture. 
Can sushi be left out for three hours?
– Sushi is a popular Japanese dish that is typically made with raw and cooked seafood, vegetables, rice seasoned with vinegar, and dried seaweed. It is more likely to contain parasites and bacteria and must be stored properly to reduce the risk of foodborne illness.
How Long Does Sushi Last in the Refrigerator? According to the United States Department of Agriculture (USDA), raw fish and shellfish can be refrigerated for 1-2 days, whereas cooked fish and shellfish can be refrigerated for 3-4 days. Sushi may be frozen, but the quality and flavor may be compromised.
How is sushi kept fresh?
Where did sushi originate? The first thing to understand is that “sushi” does not mean “raw fish.” It actually refers to a dish of rice served with a variety of fillings and toppings, including raw fish. When fermented rice was used to store fish for up to a year, sushi was initially invented as a method of preservation.
This was called narezushi, and the rice was actually discarded and only the fish consumed. A 16th-century variant called namanarezushi introduced the concept of using vinegared rice, which was consumed rather than discarded; this dish is still enjoyed today, particularly in Japan’s ancient capital, Kyoto.
Learn more from the sushi expert Masayoshi Kazato.