When buying fish for sushi, ensure it is as fresh as possible. With whole fish, check that the eyes are bright and shiny and stand proud, rather than sinking in to the sockets. Flesh should be firm and spring back to the touch. The skin should also be shiny, with virtually no odour. Fillets should be firm, yet moist and appear freshly cut, with certainly no brown tinges.
Where possible, Eat-Japan recommends that you source fish for sushi making from a recognised Japanese fishmonger, who is aware of the special measures required when preparing fish that is to be consumed raw. Atariya Foods, for example, offers a wide range of fresh, top quality fish and seafood for use in sushi
When preparing, care must be taken to ensure that there is no cross contamination on chopping boards or knives, and work surfaces and utensils should be frequently and thoroughly cleaned. Once you have cut off a slice of filleted fish to use in a piece of sushi, it must never be placed back on the chopping board, as this may transfer bacteria to the serving dish. Sushi ingredients and accompaniments such as sushi vinegar, soy sauce, wasabi , gari and green tea can also help promote hygiene.