Sushi

One of the best things you can do as a home sushi cook is become informed about both the freshness and the sustainability of the seafood you are buying. Sourcing seafood to eat raw can be tricky, as there are no legal definitions of “sushi grade” and “sashimi grade.” At the same time, the sustainability status of individual fish and shellfish changes over time, so it’s important to know the issues and keep up-to-date with the latest recommendations. Ask where your seafood comes from, how it was caught, and how it was stored and prepared to help you to make choices you are satisfied with.

Judging quality

Although “sushi grade” and “sashimi grade” are not legally regulated terms, fishmongers sometimes use these labels for their freshest fish. However, fresh fish isn’t always safe to eat raw—some fish that is sold for sushi and sashimi is frozen to kill bacteria and parasites. Guidelines from U.S., EU, and UK governing bodies specify that these fish should be frozen to not more than -4°F (-20°C), although some suppliers use the Japanese “superfreezing” technique of freezing to -76°F (-60°C) to retain maximum quality.

If in doubt, find a reliable and reputable fishmonger or fish market and ask when and where the fish was caught—it should be within 48 hours—and look to see if the fish is iced and stored properly, not sitting in melting water. Ask whether the fish has undergone freezing treatments and is safe to eat raw. Don’t be afraid to get up close and inspect the fish for freshness—use your eyes, nose, and sense of touch to judge the quality (see sections Round Fish and Flatfish and Shellfish and Roe for tips).

Fish for raw consumption should also be stored and handled separately from other fish to prevent cross-contamination. If you ask your fishmonger to fillet and skin your fish, make sure he or she uses a clean chopping board and knife.

There are also online suppliers that specialize in seafood for sushi and sashimi, but as always, make sure you understand how your fish has been handled.

▲ Freshly caught fish

As soon as they are caught, fish are chilled, vacuum packed, or frozen on the vessel.

Choosing sustainable seafood

Several factors can affect sustainability, and the situation continually evolves.

Fish species decline when they are “overfished,” or removed from the water at a greater rate than the time they need to grow and reproduce. Large, slow-growing species, such as tuna and halibut, are most vulnerable to overfishing. Choose fish from well-managed fisheries, and avoid small, immature fish that are caught before they’ve had a chance to reproduce.

Some fishing methods can cause a lot of damage to the seabed, such as beam trawls, bottom trawls, and dredges. Other methods, such as pelagic longlines, can capture vulnerable nontarget species (known as “bycatch”), such as sea birds, turtles, and dolphins.

Aquaculture, or fish farming, can be an issue when the fish are kept in open sea pens, thus polluting the surrounding water. Sometimes the fish feed used is also not sustainable. However, farming is a good option for many shellfish, which don’t require additional feed.

Organizations such as the Marine Stewardship Council certify sustainable fisheries, so look for their mark. Also refer to conservation groups, such as Seafood Watch (U.S.A.) and Oceanwise (Canada), that provide guides to sustainable seafood.

▲ selective net

This net has different-sized holes so that only the target species is caught and others can escape.