(POSTED: May 16, 2005)
About Food Safety: Shellfish Safety
Eating shellfish is a Nova Scotia tradition, from boiling lobsters in sea water to enjoying a feast of steamed mussels or fried clams. Shellfish is a delectable treasure of the Nova Scotia waters and can make any gathering even more enjoyable. Food Safety Specialists with the Nova Scotia Department of Agriculture and Fisheries want consumers to enjoy these delights by following these guidelines when purchasing, storing, preparing and serving shellfish.
Purchase shellfish only from reputable stores, markets and individuals and companies licensed by the Nova Scotia Department of Agriculture and Fisheries. These licenses should be displayed or be made available when requested by the consumer. If you want to harvest your own clams or mussels make sure the area is open for harvesting shellfish by contacting the Department of Fisheries and Oceans.
Purchase shellfish that is properly refrigerated or iced. Retail establishments should have sufficient refrigeration for shellfish storage, be clean, and provide for adequate hand washing.
> Live clams, mussels, and oysters should have closed shells. If they are slightly open, they will close tightly when lightly tapped.
> Live crabs and lobsters will show some leg movement and lobsters will curl their tail when handled.
Cooked shellfish must be held at 4°C (40°F) or lower, and displayed separate from raw fish or shellfish.
Live shellfish, for the best quality should be kept at a temperature of 3°C (37° F) when displayed or stored.
Shellfish, especially cooked shellfish, should be taken directly home and placed in the refrigerator as soon as possible. If the travel time exceeds two hours (one hour in hot weather) it should be placed in a cooler in your car.
At home keep live shellfish on the lower shelves of your refrigerator, below cooked or other ready-to-eat foods. Raw shellfish should not come in contact with cooked shellfish.
Store “live” clams, oysters and mussels in the refrigerator in containers covered with damp towels or paper towels. Never place them in water or airtight containers. Store shucked shellfish in leakproof bags or containers.
Mussels and clams in the shell (live) should be used within two or three days; oysters in the shell, within seven to 10 days. Shrimp and scallops have a shelf life of two to three days.
Live lobster and crab should be cooked the same day they are purchased.
Frozen shellfish when stored in a freezer at —18°C (0°F) can be kept for three to six months. For best eating quality they should be used within three months.
Uncooked shellfish can be frozen. Lobster is best frozen in the shell. Clams and oysters may be frozen in the shell or shucked. Shellfish frozen in the shell should be wrapped in moisture-proof wrapping. Shucked shellfish should be washed, the meats drained, and packed in freezer containers leaving a half-inch “head” space.
Always wash hands thoroughly with soap and warm water before and after handling raw shellfish.
Mussels, clams or oysters whose shells are cracked or open, and do not close tightly when tapped, should be discarded.
Lobsters that have no movement and are totally limp are dead and should be discarded.
Before cooking, rinse seafood in cold water for several seconds to remove surface dirt and bacteria.
All kitchen surface areas, cutting boards and utensils used for preparing raw shellfish should be washed in warm, soapy water and sanitized in a solution of one teaspoon of household bleach in one litre of water after use.
Steam mussels, clams or oysters in the shell for five to 10 minutes after the water begins to boil. Discard any whose shells do not open after cooking.
Submerge lobsters head first into a pot of rapidly boiling water. Start timing when the water returns to a boil and cook 10 to12 minutes for the first pound and four minutes for each additional pound.
Lobsters will continue to cook when removed from boiling water, so you can take them from the water just before they are done or drop them into iced water to stop further cooking.
When taking shellfish for a picnic or other outdoor activity, purchase only what will be consumed at the outing to avoid leftovers.
Cooked whole lobsters or crabs can be stored in air-tight containers in the refrigerator and used within two to three days.
Cooked, shucked lobster or crab meat can be stored in a sealed moisture-proof plastic bag or container in the refrigerator for three to four days.
Eating Raw Shellfish
Eating raw shellfish has a greater food safety risk than eating properly cooked shellfish.
Shellfish that may be consumed raw such as scallops, oysters and clams must be from certified growing areas.
Keep all raw shellfish refrigerated at or below 4°C (40°F) before served.
Individuals with weakened immune system, young children and elderly persons should avoid eating raw shellfish. Since cooking destroys many of the organisms that may cause food-borne illness in these high-risk groups it is recommended that only cooked shellfish be consumed.