how long can mayonnaise stay at room temperature
However, if either type of mayonnaise is cross-contaminated by foods such as raw beef, unclean utensils, or E. coli O157:H7-infected food handlers after commercially processed containers are opened, the pathogen may survive at 58C for several weeks. No one can tell you exactly how long it will last.It will usually last until you contaminate it with bacteria and medium for growth. Then it will spoil pretty rapidly, usually within hours at the wrong temp, days at a good one.p vote 3 down vote. Perishable food should not be left out more than 2 hours at room temperature (1 hour when the temperature is above 90 Â°F, 32.2 Â°C). From what I understand, it doesn't last in the backcountry. The recommended shelf-life for commercial mayonnaise, opened and inside the refrigerator, is two months.