Why You Should Think Twice Before Throwing Out Old Button Mushrooms
Mushrooms are a fairly divisive topic: You either love them or you hate them. They're versatile in the kitchen, delightful on a plate, and can supplement your diet with a unique combination of nutrients that help your body do things like prevent heart disease and fight cancer, per Healthline. It'd do you well to start including them in your meals, and it'd do you even better to know when to throw your mushrooms out — and when to keep them a bit longer.
White button mushrooms are the most common in the United States by a wide margin, making up a whopping 90% of all mushrooms consumed according to the USDA. Consuming large amounts means a higher risk of these mushrooms spoiling, so when checking over your mushrooms, look primarily for their texture and their smell. If the surface of your mushrooms are slimy, overly wrinkled, or have very dark spots, they have gone bad. But realistically, before you even get to see them, mushrooms that have gone off will emit a sharp foul smelling odor, per Delishably.
Still, when it comes to tossing your mushrooms, you should be careful not to jump the gun.
Don't judge the mushroom by its cover
Now while you do want to avoid rancid button mushrooms, or any other type, like the plague (eating spoiled food is obviously very bad for you), you also will probably want to avoid throwing out mushrooms that are actually perfectly fine to eat.
According to Cook's Illustrated, some older mushrooms may be slightly more flavorful while still remaining risk-free to eat. In a side to side taste test of differently aged mushrooms, they found that the older mushrooms may have appeared to have some slight blemishes and wrinkling, but had more depth of flavor.
The New York Times also gave a case for older, but not rotten, mushrooms, stating that if your mushrooms have dried up or aren't quite as appealing to the eye as they were when you bought them, they can still be a tasty addition to cook up with some pasta or serve over fish.
These findings are all well and good (and probably worth exploring for yourself), but it is also important to be careful with aged foods and it is imperative that you closely inspect all of the food that you prepare and consume. Mushrooms may provide some significant health benefits, but if they're spoiled, they're not worth the hassle.