Virginia Tech's expert advice for a safe and scrumptious Oyster Month

Whether enjoying the briny freshness of raw oysters on the half shell or savoring Virginia’s favorite shellfish in a cooked dish, food safety is a crucial ingredient to enjoy during Virginia Oyster Month in November.

“Oysters can be enjoyed raw or cooked by many people, but consumers should understand the risks and how those intersect with their individual health concerns,” says Katheryn Parraga, muscle food safety specialist at the Virginia Seafood Agricultural Research and Extension Center in Hampton, Virginia.

Parraga explains that while anyone can be susceptible to a foodborne illness, individuals with weakened immune systems face a higher likelihood of falling ill and experiencing more severe symptoms. The Center for Disease Control and Prevention identifies groups at higher risk, including adults aged 65 and older, children under five, and people with underlying health conditions, and advises individuals in these groups to exclusively choose fully cooked shellfish.

“Properly cooking oysters to an internal temperature of 145°F kills harmful organisms making it safer to eat, but there are also measures we can take as consumers to minimize the risks associated with eating raw oysters,” said Parraga, who shares her oyster food safety tips in Eat More Fish: The Oyster Edition — a free online consumer education program.

When dealing with any live product, bacteria is going to be present. The key, according to Parraga, is to keep the levels of bacteria under control.

Some types of spoilage microorganisms are more easily detected than others. Parraga says funky odors and odd textures are reliable indicators of spoilage, but the problem are the pathogenic bacteria, an oyster with Vibrio bacteria that can cause disease may not look, smell, or even taste different from any other oyster.

“Oysters are filter feeders, so when naturally-occurring Vibrio bacteria, or other potential contaminants that can get people sick, are prevalent in the water, they can accumulate in oysters,” she said.

The Virginia Cooperative Extension initiative ‘Eat More Fish’ was designed to break down barriers to people bringing seafood into their home kitchens and support the Virginia seafood industry, which provides over $1.1 billion boost to the state’s economy. The oyster edition of the program includes presentations covering tools to find and buy Virginia oysters, insights for dining out at restaurants, cooking and shucking demonstrations, and information from the state agencies working to ensure the shellfish we eat from state waters is safe. Resources from the program are available online for free.

"No raw seafood can be guaranteed to be bacteria-free, but our local and state agencies do monitor harvest conditions and processing practices to protect consumers so they can feel secure when enjoying oysters or other seafood products,” Parraga said. “Still, consumers are a key link in the food safety chain."

Parraga offers the following tips:

Transporting Oysters

• Use a cooler and ice or cold packs to keep shellfish chilled post-purchase or harvest.
• Oysters from seafood markets should stay alive until just before cooking or shucking.
• Oysters from seafood markets are actually alive and should remain so just before cooking or shucking and serving.
• Do not store shellfish in water, as they will die and may spoil. If using ice, keep it well drained.

Storage Guidelines:

• Keep live oysters at 45°F or lower to preserve freshness. Shucked oysters should be stored below 41°F.
• Keep cooked and raw shellfish separate to prevent cross-contamination.
• Prevent dehydration in the fridge by avoiding direct exposure to the fan and covering live oysters with a damp paper towel.

Shelf-Life:

• Live oysters: Up to a week if proper storage guidelines are followed.Shucked oysters in the fridge: Up to three days; In the freezer: Up to three months.
• Cooked shellfish in the fridge: Up to two days; In the freezer: Up to three months.
• Thawed shellfish: Up to two days; do not refreeze.

Handling and Preparation:

• Ensure oysters are alive before cooking or shucking. Upon tapping the shell, oysters that emit a hollow sound or do not close and remain open are dead and should be discarded.
• To fully cook oysters, bring oysters to an internal temperature of 145°F degrees; use a clean food thermometer.

About Parraga

Katheryn Parraga-Estrada, Muscle Food Safety Extension Specialist, is based out of the Virginia Seafood Agricultural Research and Extension Center in Hampton, Virginia, and is a faculty member in the Virginia Tech Department of Food Science and Technology. Her work through Virginia Cooperative Extension focuses on improving the understanding and application of food safety research through education, training, and technical guidance for the production of safe and quality foods. She spearheads the Eat More Fish Program, a consumer education initiative that brings together expert voices to empower people to incorporate local seafood into their own kitchens to enjoy at home.

Schedule an interview

To secure an interview with Parraga, contact contact Margaret Ashburn in the media relations office at mkashburn@vt.edu or 540-529-0814.