How long can unrefrigerated coffee sit out for?

Coffee that is brewed and left at room temperature will start to degrade in quality within 30 minutes to 4 hours, depending on the temperature of the room. The higher the temperature, the faster the coffee will degrade. Factors that can affect the rate of degradation include the type of coffee beans, the brewing method, the amount of coffee grounds used, and the amount of time the coffee has been sitting out at room temperature. Cold brew coffee is more stable and can last longer than hot brewed coffee at room temperature. However, it is still best to refrigerate coffee as soon as possible to maintain its quality and flavor.