Fortunately, you easily can tell an oyster is spawning. “Spawning oysters look foamy and milky, even a little slimy,” says David Lentz, executive chef at the Hungry Cat in Hollywood. In theory, a good restaurant should never serve a spawning oyster.
If it looks veiny, with bluish or whitish channels through the flesh, that's a sign that it's getting ready to spawn and is filled with gamete, not glycogen. Prick a spawny oyster and its liquid will look milky.
Based on that definition, there are some signs when an oyster has gone bad: The oyster is gaping open, which means it is weak or dead. The oyster is dry, which means it is weak, injured or dying. The oyster smells or tastes different from harvest.
Symptoms. Most Vibrio infections from oysters result in mild illness, including diarrhea and vomiting. However, people with a Vibrio vulnificus infection can get very sick. As many as 1 in 5 people with a Vibrio vulnificus infection die.
In the northern hemisphere, the old rule that native oysters should only be eaten when there's an 'r' in the month still holds true; so eat oysters from September to April. During the summer months they're busy spawning, and their flesh becomes unpleasantly soft and milky.
A fresh oyster should ideally have the scent of an ocean breeze and feel ice cold to the touch. If the oyster feels warm or gives off an offensive, pungent odour, then it is possibly about to go bad. Be sure to check this step before topping it with any sauces or garnishes, as those could potentially mask the odour.
Inspect the bottom of the shell for broken or damaged areas, as this outward sign of trauma could mean the oyster was damaged in transit. Additionally, the best oysters are never wrinkled or dried out. Other positive visible cues that illustrate they were just harvested include firmness and plumpness.
Unfortunately, one bad oyster can get you so sick you'll be out of commission for days. Food poisoning from oysters is somewhat rare, but if it gets you, it's important to monitor your health closely for at least three days, especially if you have other health complications.
Symptoms can include vomiting, diarrhea, nausea, stomach pains, severe weakness. Vibrio infections can also cause skin rashes and blisters, shaking chills, and high fever. Hepatitis A can cause yellowing of the skin or whites of the eyes. Some of the illnesses can be quite serious and require quick medical attention.
Shelf Life: A live oyster is good to eat. When properly cared for live oysters will live in your refrigerator for 10 to 21 days. Are they alive? When oysters are dead in their shells they are no longer suitable to eat.
Shelf Life
How long do your shucked oysters last? Shucked oysters will have a good-through date. If they go past this date, you'll want to discard them. Shucked oysters typically have a 10-14 day refrigerated shelf life upon receipt.
You may have heard the saying that you should only eat oysters in months that contain the letter "r," meaning oysters harvested in the warmer summer months of May through August were not safe for consumption. However, oysters are now sold and consumed year-round with little to no worries.
Unless you are going to eat your oysters straight away, it's better to buy them unopened. Given the proper care, oysters will live for 5-7 days after being harvested. You can keep live oysters in the fridge.
Cooking the oysters should be a process you handle VERY delicately! If you overcook your oysters, they'll end up feeling and tasting rubbery. Don't let your oysters go to waste! There's a little trick to knowing when your oysters are done cooking.
The best way to store them is in their bag, inside a bowl with a damp cloth over the top. But please: Do not store the oysters directly on or underneath ice. Oysters will die if they sit in fresh water. You can keep them on a tray of ice for an hour or so but avoid letting them sit in a puddle of fresh water.
You can get very sick from eating raw oysters. Most Vibrio infections from oysters result in only diarrhea and vomiting. However, some infections, such as those caused by Vibrio vulnificus, can cause more severe illness, including bloodstream infections and severe blistering skin lesions.
The bug is most commonly found in coastal waters where oysters are harvested, and certain strains of it can make you sick, according to the CDC. Each year, the CDC estimates nearly 80,000 people get sick with vibriosis (the infection caused by the vibrio bacteria) and 100 people die from it.
Quick steaming or cooking until the shells just open may not be enough to protect against norovirus illness. Norovirus can survive cooking temperatures up to 140°F so cooking to 145°F provides a margin for safety. Avoid eating raw oysters like oyster shooters and oysters on the half shell.
"Dead raw oysters run a greater risk of being infected with viruses and bacteria that can have a negative impact on your health—although the overall risk is relatively low," she says. Low or not, that's why they are in fact alive or freshly killed to keep you safe.
So the answer to your burning question (Is food poisoning contagious?) is yes, the bugs that can cause food poisoning are contagious. While you can't avoid all possible food poisoning scenarios, there are things you can do to reduce your risk.
Healthy oysters, like our White Stone Oysters, are plump, glossy, in their own liquor, and light tan in color. If your oyster is bad, it will have a cloudy, dry, and withered appearance. Contaminated oysters will be grey, brown, black, or pink.
One of the most important steps in knowing how to prepare oysters includes cleaning them properly, which is especially true if you want to eat them raw. Scrub away dirt and debris from each oyster under cold running water to ensure they're completely clean.
Oysters should smell like the ocean, according to Brue. Anything that smells fishy should be avoided. Look for seaweed and small crustaceans. Brue says that fresh seaweed on the outside of an oyster is a sign of freshness.