As a food safety expert, I can tell you that the time it takes for milk to spoil at room temperature can vary depending on several factors, including the initial temperature of the milk, the room temperature, and the type of milk (e.g., whole, skim, or non-homogenized). Generally, milk can spoil rather quickly at room temperature, often within a few hours. Bacteria that are naturally present in milk can multiply rapidly in warm conditions, leading to spoilage. The key signs of spoiled milk include an off smell, curdling, or a change in color. It's important to note that consuming spoiled milk can lead to foodborne illness. Therefore, it's always recommended to refrigerate milk and consume it within the expiration date or within a week if it's been opened.

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In general, perishable foods like milk should not sit out of the refrigerator or cooler for longer than two hours. Cut that time down to an hour in the summer if the temperature reaches 90 degrees F. After that time frame, bacteria can start to grow.read more >>