Who doesn’t love a nice wine and cheese party? There’s something relaxing and sociable about carving a slice of Asiago off the block, or nibbling on a cheddar-topped toothpick. Cheese is the ultimate evening party food; it’s a perfect complement to company and conversation. But what happens when the party ends, and everyone goes home? As your friends trickle out the front door, you begin to feel overwhelmed by the serving plates left on the table and counters. You decide that the mess is too much to deal with at ten on a Friday, and that you would much rather make sense of the mess after you have time to relax and sleep in. As you go to bed, though, you wonder: is it safe to leave cheese out overnight, or have you consigned plates of perfectly good cheese to the garbage chute?


In our last blog, those of us at Bluegrass Dairy and Food discussed the potential risks leaving a stick of butter out to soften could pose to a person’s health. Here, we take on similar questions:


How long can you leave milk and its products at room temperature, and what are the risks if you leave something out for too long?


For milk, the answers to the above are simple:


Don’t leave a glass or carton out for more than two hours – or even one, if the temperature is over 90 degrees Fahrenheit. If you do, the milk you were hoping to pour over your cereal or into your coffee might just spoil, turning sour and chunky. At worst, it might even make you sick!


The US Food and Drug Administration officially classifies milk and its derivative products as a TCS (Time/Temperature Control for Safety) food group. This label indicates that a food may become dangerous when left out at an unsafe temperature; generally, milk should be kept at 41 degrees Fahrenheit or lower to be considered safe. Some recommend keeping milk cartons on the bottom shelf – i.e., the coldest section – of a refrigerator to ensure safe storage. Milk left out for longer than four hours in warm weather is at risk of spoilage or bacterial contamination, and as such should never be consumed.


That said, most dairy products can be left out at room temperature for two hours without any adverse effects. Milk, cream, and yogurt all fall within this rule – so don’t make the mistake of leaving a cup of yogurt on your desk as a workday treat. Leaving a dish out for a later snack might just make you sick!


Cheese is somewhat of a different story. Unlike milk or yogurt, most cheese can sit out for a few hours, especially if it’s been well-aged. Hard cheeses will likely be fine if left at room temperature overnight, given their relative lack of moisture and long aging processes. Soft cheeses such as brie or Camembert face more risk because the contain more moisture for bacteria to access and grow within. However, leaving soft cheeses out for a brief period of time – an hour or so – will impart a deeper flavor and better texture than chilling!


So, should you leave cheese out overnight? Probably not – but doing so also probably won’t make you sick if you stick to the hard cheeses.