The best way to make sure you are selecting fresh fish is to buy fish that is in season and to know what to look for. However, different fishes have different harvesting seasons and different characteristics when fresh. Furthermore, many species of fish need to be stored or cured in a special way to ensure that the flavor and texture remains high-quality enough for sushi. Here is a list of different types of fish and seafood and how to buy them and store them to ensure that they are fresh and safe to eat.
More than any other fish, mackerel should always be eaten as fresh as possible. Mackerel should never be eaten raw except for right after it is caught – raw mackerel is rarely eaten outside of Japan. Mackerel is notorious for spoiling very quickly, and as it spoils, chemicals form that can cause an allergic reaction in many people. It’s best to buy mackerel in season, which begins in May and ends in September. When purchasing mackerel, buy it live or on ice while the blood is still red. As soon as the fish is in the kitchen, it should be cured for three to four hours in a salty bath with vinegar. Drain it for another hour to extract the moisture. Then, wash the mackerel in rice vinegar, and it is ready to be served as sushi.
Purchase red snapper in the summer as most of it is harvested at this time in the United States from the Gulf of Mexico. There are two methods for storing red snapper. To bring out the flavors of the fish, refrigerate it for several hours. This will reduce moisture and amino acid levels to bring out a more intense flavor. However, the texture grows softer when refrigerated, so if texture is a main priority in your nigiri, red snapper should not be refrigerated, but instead should be bought alive or fresh and kept on ice for as little time as possible before it is eaten.
You are most likely to find fresh salmon during the summer or early fall, when they are in season. To check salmon for freshness, feel the meat to make sure it is firm. If you will be consuming the salmon raw, be sure to choose farm-raised salmon rather than wild salmon, as it is far less likely to contain parasites. Most Atlantic salmon – the most widely available – is farmed, whereas Pacific salmon is usually caught in the wild.
Sardines taste best when harvested in the fall or early winter. Like mackerels, sardines spoil very quickly. They should only be eaten raw if they are completely fresh, when they will have a sweet, rich flavor. It is best to purchase sardines alive, but unfortunately, they require large aquariums to survive and are hard to find alive in supermarkets. If live sardines are not available, the sardine should be fried or grilled for consumption.
Sea bass are harvested in the summer, so if possible buy during this period of time. If possible, the Japanese sea bass should be used, but it may be hard to find in the United States. Other sea bass can also work well for sashimi or nigiri. Look for sea bass with dark pink gills and firm, white flesh. Unlike most saltwater fish, the sea bass is usually prepared arai style – by rinsing the cut flesh in a bowl of warm water, then shocking it by plunging it into a bowl of ice water.
Sea cucumbers are best when purchased in the winter, during their harvest season. This is also when they are at their sweetest. When choosing a sea cucumber, look for red flesh as they are the softest and most flavorful. Also, as with most seafood, be sure that the meat is firm and that the flesh is devoid of any obvious blemishes.
Due to their thick shells, it is sometimes difficult to feel and view the flesh of crabs, lobsters, clams, scallops and oysters to determine whether they are fresh. Therefore, it is best to buy live shellfish. They can be kept alive in a tank or a covered bucket of water before they are prepared for sushi, but make sure they have ventilation. The water should also be changed frequently to give them plenty of oxygen. Crab and lobster can also be wrapped in paper and stored in the refrigerator. They will stay alive for about a day in storage. Always cook crab, lobster and other bottom-feeders before consumption, since they contain many harmful bacteria. Scallops, oysters and clams can be eaten raw as long as they are fresh.
The shrimps with the best flavor for sushi are the karuma shrimp or the black tiger shrimp, but any shrimp will do. The freshest shrimp should be purchased live. If live shrimp is not available, but you are in a coastal shrimping region, look for shrimp on ice that are grey-white and translucent. If you are not near the coast, look for whole, frozen shrimp with the shell still intact. Never buy shrimp with the vein already removed, because you will not be able to cut them for nigiri without splitting them in two.
If possible, squid should be purchased and eaten in the spring and summer, when it is in season. The freshest squid will have clean eyes and translucent flesh. The flesh quickly turns opaque, so if you find squid with see-through flesh, you know it is fresh enough to be eaten raw. Wrap it in food-safe paper for storage. It should be frozen immediately, or refrigerated and eaten as soon as possible. The ink of the squid is found in a silver sack and can be stored and used as a flavoring in many dishes. If fresh whole squids are not available, you can buy it frozen, since it freezes well.
Red tuna – also known as Northern bluefin tuna – is one of the safest fishes for raw consumption and the most popular type of tuna for sushi. Ahi tuna – the yellowfin tuna – or albacore are also excellent for sushi, but are slightly less safe to eat in their raw forms. When purchasing tuna, look for firm flesh that is pink to dark red. Avoid fillets where white lines are visible in the meat. These white lines are sinews that have an unpleasant texture when consumed raw.
Yellowtail taste best as nigiri or sashimi when eaten in the winter. This is when they have the oiliest texture and pinkest flesh. It is best to eat yellowtail in the winter. Look for yellowtail with clear eyes and firm, springy flesh.