Eating raw oysters can carry a risk of food poisoning because shellfish can contain harmful bacteria and viruses because of the way they feed. Oysters filter large volumes of water to get their food and any bacteria and viruses that may be in the water can build up within the oyster.
Controls before and after commercial harvesting provide good protection against harmful bacteria, but it can be difficult to remove viruses from live shellfish. Thorough cooking will destroy these viruses but many shellfish are eaten raw or only lightly cooked so may still contain viruses when eaten. Brighton & Hove City Council’s Food Safety team want people to enjoy oysters and have issued some simple guidelines:
- Only buy from a reputable fishmonger, retailer or supplier.
- Upon tapping, any open shells should close.
- The oyster should smell clean and briny
- Always keep the oysters stored with the curved side downwards. This helps to retain the fluid in the shell and keep them alive.
- Store the oysters in a deep bowl (to prevent leaks) and away from other open foods.
- Keep them cool (4°C to 8°C is good). Remember, these are live animals so you don’t want to freeze them.
- Do NOT re-immerse oysters in water. They will have been properly purified at the purification centre and any further immersion risks re- contaminating them.
- If stored as shown above the oysters should last at least 5 days.
- Wash your hands thoroughly before opening the oysters.
- Ensure that the knives and other equipment (including gloves if you wear them) used for opening the oysters and the area you are working in are all clean before you start.
- Check that the outside shells of the oysters are clean and avoid pushing any mud or bits of shell into the oyster as you open it.
- Both shell and meat should be clean white, with a little pink or gray highlighting being acceptable, beneath a glassy sheen. Any oyster whose meat or liquor looks cloudy, brown, gray, blackish or reddish, or which smells brackish, should be discarded.
- It is not recommended to eat oysters and drink spirits at the same time.
- Serve promptly.
- Some people have can have an allergic reaction to oysters so if you are planning to serve them to someone else it may be worth letting them know
We also have some printable documents for businesses about the requirements relating to live bivalve molluscs:
For further advice please contact the Food Safety Team on 01273 292 161 or by email email@example.com.
More guidance on hygiene can be found on our Food Safety Guidance page.