As a food safety expert, I can tell you that the safety of yogurt left out at room temperature depends on several factors, including the initial temperature of the yogurt, the ambient temperature of the room, and how long it has been out. Generally, yogurt can be safely left out for a short period, typically up to 2 hours. This is because yogurt, like other perishable foods, can grow harmful bacteria if left at room temperature for too long, which is considered to be above 90°F (32°C). After 2 hours, the risk of bacterial growth increases significantly, and the yogurt may not be safe to eat. It's always best to refrigerate yogurt or any perishable food as soon as possible to maintain its quality and safety.

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According to the US Department of Health & Human Services, you should throw out yogurt if it's been out at room temperature for more than two hours. If the temperature is higher than 90 degrees Fahrenheit, you only have one hour to eat that yogurt sitting out of the refrigerator.read more >>