We've all had that moment when we wonder if something has really gone bad. And that tends to happen a lot when you're cooking for one. Your mom, best friend, and Google all have different answers, but the best rule of thumb is to avoid these three red flags:

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1. Green Potatoes

If it looks like Kermit, chuck the potato. The green hue can signal the harmful toxin solanine, which can't be cooked off. The same advice goes for any potatoes that taste bitter.

2. Mold

This is kind of an obvious one, but make sure you cut off not only the moldy parts but also an inch perimeter around that spot. And if the food is overgrown with mold, toss it. Exceptions, such as blue cheese, do exist, but if you're unsure, it's best to play it safe.

3. Rancid Nuts and Oils

Stay away from nuts and oils that make you go "ew!" If it tastes really gross, it's probably rancid, which means the fats and oils have started to decompose. These have a lower chance of making you sick, but trust us, you won't want to eat them anyway.

The good news is lots foods that look bad are probably still OK to eat. Browning apples, bananas, and potatoes are totally fine, since the outer skin of these foods protects the inside. Same goes for food that's bruised (you may want to remove the bruised portion). Surprisingly, sour milk (as long as it's pasteurized—and most dairy in the U.S. is) likely won't make you sick, even if the smell makes you cringe. You may not want to drink it, but it's safe to use for baking or other recipes that require it.

(h/t Lucky Peach)

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