Q: I eat steel-cut oats for breakfast. To save energy and time in the morning, I bring them to a boil the night before, then leave it out, covered, overnight. Is this safe?
A. Just because a dish doesn’t have something we consider perishable, such as a dairy or animal product, we sometimes assume it’s safe at any temperature. But when water is added to a dry food, that’s not the case.
Benjamin Chapman, the food safety specialist with the N.C. Cooperative Extension, says leaving warm oatmeal out overnight is risky.
“Depending on how much water is added, and if there’s a pathogen in the dry oats (like salmonella, which probably isn’t uncommon), you can get crazy growth at ambient temperatures.”
In other words, if there is bacteria present, it has the right conditions to reproduce quickly, producing enough cells by morning to make you sick. If you need to make oatmeal in advance, either cook it completely and refrigerate it to reheat later, or use a slow cooker to keep it hot overnight.