Food that requires refrigeration will spoil at 60 F degrees if it's left out too long.
Food can begin spoiling at 40 F or above after a few hours depending on the type of food.
Some types of foods spoil faster than other types of foods.
All refrigerated food should remain beneath 40 degrees Fahrenheit to prevent bacteria build up.
Once the temperature exceeds this point, your food begins to run the risk of contamination.
The FDA recommends that all perishables left at room temperature for more than two hours be discarded.
Bacteria grow most rapidly between 40 degrees Fahrenheit (4.4 degrees Celsius) and 140 degrees Fahrenheit (60 degrees Celsius), doubling in amount every 20 minutes.
Most dairy can go unrefrigerated for 2 hours before it spoils.
However if the temperature is warmer than 90 F then the dairy can spoil when left out at room temperature for an hour.
If the temperature is 90 F or warmer then the dairy should not be left out longer than an hour but if the temperature is lower than 90 F then the dairy can safely be left out for 2 hours.
Milk can sit out at room temperature for up to 2 hours.
After 2 hours the milk when left at room temperature can begin growing bacteria and going sour and should be thrown out.
Once you buy the milk it should be promptly refrigerated and if you're gonna be awhile before you can get the milk home it's best to place the milk in an ice chest to keep it cold.
Milk left out overnight should be thrown out as well because it likely has spoiled by that time and could contain bacteria that you may not be able to see.
Milk that has actually gone bad will also smell sour and you wouldn't want to drink it anyway.
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.
The FDA asserts that you should never keep unopened milk out of the refrigerator at room temperature for more than two hours.
However, this window reduces as the temperature rises.
This means that when the temperature exceeds 45°F, unopened milk can last up to an hour.
While there are no set recommendations, most research suggests that as long as it's been stored properly, unopened milk generally stays good for 5–7 days past its listed date, while opened milk lasts at least 2–3 days past this date.
If your milk doesn't smell like milk, it's likely expired.
Milk that's gone bad exudes a foul odor — and it will be very obvious upon taking a whiff.
This is the best procedure for determining if your milk has gone bad.
"The odor is very obnoxious.