When shopping for eggs, it’s common for many people to check the cartons for cracks before making a purchase. But what happens if an egg cracks during transport, say in the car or while moving it to the fridge? Is it still safe to eat?
According to Bill Marler, a food safety advocate from Washington, the answer is a definite no. He advises that broken eggs should be discarded. Marler explains that cracked eggs present a higher risk for Salmonella bacteria, which can seep in and multiply. Interestingly, eggs with cracks are statistically more likely to test positive for Salmonella compared to intact ones, even if the latter are contaminated with feces.
Donald Schaffner, a food science professor at Rutgers University, notes that the significance of the crack size and how long it’s been there plays a critical role. If it’s a small and recent crack, the possibility of bacterial growth is minimal. However, larger or older cracks mean a higher chance of bacteria entering the egg, potentially leading to spoilage.
Additionally, the Centers for Disease Control and Prevention (CDC) reinforces that any broken or dirty eggs should be completely discarded. Schaffner mentions that cooking eggs thoroughly can kill Salmonella. Another alternative is using freshly cracked eggs in recipes that require full cooking. Creative chefs may even fully cook cracked eggs for their pets.
There is a small potential for other pathogens to infiltrate the eggs, which could create heat-stable toxins that cooking might not eliminate, but Schaffner believes this scenario is quite rare. The CDC estimates that eggs are responsible for about 1.35 million Salmonella infections annually, as noted by food safety expert Darin Detwiler.
Salmonella can sometimes infect a laying hen’s reproductive tract, meaning even clean-looking eggs can harbor bacteria inside the shell. This is part of why some countries have implemented vaccination programs for poultry to combat Salmonella. Yet, Detwiler and Schaffner agree that the overall risk for consumers remains low, even with the possibility of contamination before the shell forms.
Interestingly, Schaffner points out that Salmonella is mostly found in egg whites, which have natural preservatives that hinder bacterial growth. However, if the membrane separating the egg white from the yolk breaks down, bacteria can migrate to the yolk, allowing potential growth. Fortunately, this membrane breaks down more slowly in refrigerated conditions, which is why storing eggs at cooler temperatures is recommended.
Ultimately, the risk of cross-contamination is real, which is why Marler insists that if there’s any doubt about an egg’s safety, it’s best to dispose of it. Schaffner emphasizes that safe food handling practices—cleaning, separating, cooking, and cooling—are vital to prevent foodborne illness.
