Tip Sheet decided to investigate. We sampled sushi from plastic packages that had been frozen for weeks–even months–and then defrosted in an ordinary microwave. It seemed a risky proposition. But the fish tasted good, much better than store-bought sushi in North America and Europe. The rice is a bit on the sweet side and the fish slightly firmer than the fresh, more tender sushi. But the quality of Kairinmaru’s sushi is surprisingly high, even when it comes to more fragile, short-shelf-life items like salmon roe and mackerel. For those who can’t rough the raw, try the pumpkin, scallion and other vegetable roll options. Kairinmaru president Hajime Sawatari plans to try and corner the store-bought-sushi market.
How do they do it? When fish is frozen, the areas of water between cells expand by nearly 10 percent, turning into jagged ice crystals that injure the cells and destroy sushi’s taste and texture. Kairinmaru’s method, using only natural additives, removes water from the fish meat while simultaneously strengthening the walls of the cells.
The next problem is rice. Normal freezing and thawing of sushi results in the bleeding of moisture out of the fish while the rice becomes dry, lacking the gluey texture of traditional sushi rice, because the starch and water content separate. Company technicians have come up with a way to freeze sushi so fast that there’s no time for the water and starch to separate.
