Experts Warn Against Boiling Unwashed Eggs and Rice Together Over Food Safety Risks

Nutrition experts have advised Nigerians to stop boiling unwashed, unpeeled eggs together with rice in the same pot, warning that bacteria present on eggshells could contaminate the rice during cooking. The warning was issued by registered dietitian-nutritionists who said the practice, which is sometimes used to save cooking time and fuel, could create a food-safety risk when proper egg hygiene is not observed. According to the experts, microorganisms including Salmonella and Escherichia coli can be present on the exterior of eggshells. When an unwashed egg is placed directly into a pot of rice, bacteria from the shell could potentially come into contact with the rice and cooking water. The concern is particularly relevant during the early stages of cooking, when the water is heating up but has not yet reached a sustained boiling temperature. The experts therefore recommended preparing the two foods separately as the safer option, rather than placing unwashed eggs directly into a pot of rice. Why eggshells are a concern Eggs can become contaminated with microorganisms during production, handling, transportation or storage. Although an intact eggshell provides a natural barrier around the contents of an egg, bacteria on its exterior can become a source of contamination when the shell comes into contact with other food. The PUNCH report quoted dietitian-nutritionists as explaining that cooking does not necessarily eliminate the possibility of contamination occurring during the heating process. One of the concerns is that rice is already being prepared in the same water in which the egg is placed. If the shell carries harmful microorganisms, they may be transferred to the cooking environment before temperatures become high enough to destroy them. The experts therefore advised against putting unwashed eggs directly into rice during cooking. Nigerian study examined the practice The warning is also supported by research specifically examining the safety of cooking rice and unshelled eggs together. A 2023 study published in the IOSR Journal of Environmental Science, Toxicology and Food Technology investigated rice cooked in the same medium as eggs. Researchers tested rice cooked with both washed and unwashed eggs and examined the samples for Salmonella and E. coli. The study reported that rice cooked with washed eggs showed no detectable Salmonella or E. coli in the tested samples. However, samples from rice cooked with unwashed eggs recorded microbial counts for both organisms. The researchers reported E. coli at 1.87 × 10⁴ CFU/g and Salmonella at 1.11 × 10⁴ CFU/g in the unwashed-egg sample. The researchers concluded that individuals should avoid cooking rice with unshelled eggs in the same medium, while also noting that further research could examine other organisms associated with eggs. The findings provide context for the current warning, particularly regarding the condition of the eggshell before cooking. The issue is cross-contamination The main food-safety concern is therefore not that rice and eggs are inherently incompatible foods. Rather, it is the possibility of cross-contamination between the eggshell and the rice. Food-safety guidance generally recommends keeping raw eggs and other potentially contaminated foods separate from foods that are ready to eat or being prepared for consumption. The United States Food and Drug Administration, for example, advises consumers to separate raw eggs from other foods during handling and to cook eggs thoroughly to destroy harmful bacteria. The agency also notes that some raw eggs can contain harmful bacteria and recommends thorough cooking of egg dishes. This principle is particularly important when an egg is placed directly into another food instead of being handled separately. Why some Nigerians use the method Cooking eggs alongside rice is not necessarily a new practice. For some households, placing eggs into a pot of rice can be a convenient way of preparing both foods simultaneously. It may also reduce the number of cooking utensils required and, where cooking gas or electricity is expensive, potentially reduce the time spent using a cooker. The practice is therefore largely driven by convenience and household cooking habits. However, the experts' recommendation is that convenience should not take priority over basic food-hygiene measures. Cooking the rice and eggs separately removes the direct contact between the eggshell and the rice and makes it easier to handle each food according to its own preparation requirements. Washing eggs does not eliminate every food-safety concern The Nigerian study also highlights an important distinction that should not be overlooked. Its results showed a difference between rice cooked with washed eggs and rice cooked with unwashed eggs, with the tested washed-egg sample showing no detectable Salmonella or E. coli. However, this should not be interpreted as proof that washing eggs makes the practice completely risk-free. Food safety depends on several factors, including how eggs are handled, stored and cooked. Washing eggs can also have different implications depending on how it is done and the condition of the eggs. The broader recommendation from the experts is therefore straightforward: cooking eggs and rice separately is the safer approach. Nigerians urged to prioritise food hygiene The warning comes amid wider efforts to encourage safer food-handling practices in Nigerian households. Foodborne illnesses can occur when harmful microorganisms are transferred between foods, cooking surfaces, utensils or hands. Basic measures such as keeping raw foods separate, maintaining clean cooking surfaces and thoroughly cooking foods can reduce the risk. The FDA recommends cleaning hands and surfaces, separating raw foods from other foods, cooking food to safe temperatures and refrigerating perishable foods promptly. For Nigerians who currently place eggs directly into rice while cooking, the experts' advice is to prepare the foods separately. While the practice may save time or cooking fuel, the potential for contamination from an unwashed eggshell makes separate preparation the safer choice. The available Nigerian research also suggests that the condition of the eggshell matters, with significantly different microbial findings reported between washed and unwashed eggs. The issue, therefore, is less about rice and eggs being incompatible and more about how the egg is handled before it comes into contact with the rice. For households seeking to minimise food-safety risks, cooking the rice and eggs separately remains the simplest precaution.