Wow, I’m only learning this now.

Temperature plays a critical role in the preservation of mayonnaise. At room temperature, bacteria can multiply rapidly, increasing the risk of spoilage and foodborne illness. Refrigeration slows down bacterial growth, thereby extending the shelf life of mayonnaise. Ideally, mayonnaise should be stored at temperatures below 40°F (4°C) to ensure its safety.

Storing mayonnaise on the counter can lead to several risks, including the growth of harmful bacteria such as Salmonella and Listeria. These bacteria thrive at room temperature and can cause severe foodborne illnesses. Additionally, mayonnaise that is left out for too long may develop off-flavors and an unappealing texture, making it unsuitable for consumption.

Mayonnaise should not be left out at room temperature for more than two hours. In hot weather, this time is reduced to one hour. Beyond this period, the risk of bacterial growth increases significantly, and the mayonnaise should be discarded to prevent the risk of foodborne illness.

Spoiled mayonnaise may exhibit several signs, including an off smell, a change in color, or a separation of the emulsion. If the mayonnaise develops a sour or rancid odor, it is a clear indication that it has gone bad. Additionally, any visible mold or discoloration is a sign that the mayonnaise should not be consumed.