Which item should always be stored in refrigeration?

Mayo, or mayonnaise, should always be stored in refrigeration after it has been opened. This is because mayonnaise is a perishable condiment that contains eggs and oil, making it susceptible to bacterial growth if left at room temperature. Keeping mayonnaise cold helps to maintain its quality, texture, and safety for consumption.

While honey mustard and teriyaki sauce may have preservatives that allow them to be shelf-stable for a period of time, they do not require refrigeration for safety in the same essential way that mayonnaise does. Thousand Island dressing, which typically contains mayonnaise as a base, should also be refrigerated once opened, but it is primarily the mayonnaise component that necessitates cold storage to prevent spoilage.