Why You Should Think Twice Before Eating Leftover Mushrooms

It happens all the time: You make a big bowl of pasta for dinner and can't finish it all. That's okay. You can always reheat it for lunch tomorrow. Or can you? Depending on what ingredients are in your sauce and how long it's been sitting out, you may have to reconsider that notion.

While microwaving day-old dinners may be one of the most convenient ways to repurpose a meal, there are some things it does not work for, and one of them is mushrooms. This is not because they could become rubbery like seafood or explode like grapes, but because they could potentially make you sick (via Independent).

Expert Home Tips notes that if mushrooms are not refrigerated quickly after being cooked, their complex enzymes and proteins will begin to break down. This makes them susceptible to dangerous bacteria, which can be worsened by the reheating process — microwave or otherwise. It is worth noting, though, that this only applies to fresh mushrooms, as processed mushrooms, like those bought frozen, dried, or in a can, do not pose these risks (via Clark.com).

To eat, or not to eat?

So how long is too long? Still Tasty notes that in order to stay safe and protect yourself from bacteria, the cooked mushrooms cannot be left at room temperature for more than two hours before going into the fridge. They also recommend storing them in an airtight container or sealed plastic bag. You can also freeze sautéed mushrooms for several months and reheat them at your convenience, according to Good Cheap Eats, but you need to freeze them immediately after you finish cooking them.

If you put the mushrooms in the refrigerator within that time frame, and your reheating simply involves last night's leftovers, you should be fine. According to the European Food Information Council (EUFIC), if cooked mushrooms are kept in the fridge for no longer than 24 hours, they can safely be reheated. The EUFIC recommends reheating to a temperature of 158 degrees Fahrenheit or 70 degrees Celsius (via Business Insider).

If you're sure you've managed to keep everything within that time window, then your mushroom pizza or pasta sauce can still be reheated. If you're not, you may want to heed My Recipes' advice and eat them cold, or simply cut your losses and toss the leftovers. Although not life threatening, nobody wants to deal with an upset stomach.