I had made some mashed potatoes and I accidently left them out for 3 hours, were they safe to serve after being left out?A:
If they were just mashed potatoes, they were probably ok to leave out. However, the issue is usually what was mixed into the mashed potatoes milk & butter can be a problem with dairy more so than olive oil or margarine.
Here are the general guidelines:
Once cooked and left out at room temperature holding hot food needs to be 135°F or above and holding cold food should be at 41°F or below.
Also from a web site on food safety called stilltasty.com “Big offenders include rice salads, pasta salads and that bowl of mashed potatoes, if it's not put into the fridge a couple of hours after serving it. These starchy dishes are breeding grounds for Bacillus Cereus, a microbe that can cause severe vomiting or disabling diarrhea.”