Mayonnaise is a common kitchen staple, but improper storage and handling can turn it into a food safety risk. Most store-bought mayonnaise is relatively safe because it is made with pasteurized eggs and acidic ingredients that help slow bacterial growth. However, once opened, the jar can become contaminated through dirty utensils, contact with other foods, or exposure to warm air. Simple habits, such as using a clean spoon and closing the lid properly, can help prevent contamination.

Temperature is one of the most important factors in keeping mayonnaise safe. It should be stored in the refrigerator at or below 40°F (4°C) and should not be left sitting on the counter for long periods. According to food safety guidance, perishable foods left at room temperature for more than two hours may become unsafe, and the limit drops to one hour when temperatures exceed 90°F (32°C). This is especially important during outdoor meals, parties, and warm weather.

Homemade mayonnaise requires extra care because it often contains raw or lightly cooked eggs and generally has a shorter storage life than commercial products. To reduce the risk of foodborne illness, prepare it with pasteurized eggs, refrigerate it promptly, and follow reliable storage guidelines.

Finally, always check mayonnaise before using it. Unusual smells, changes in color, or an altered texture may indicate spoilage, although harmful bacteria can sometimes be present without visible signs. Keep the jar tightly sealed, avoid cross-contamination, and return it to the refrigerator immediately after use. Proper storage and clean handling are simple ways to enjoy mayonnaise while reducing the risk of food poisoning.