How to Tell If Mushrooms Are Bad (Because the Last Thing You Need Is a Spoiled Shiitake)

Some people love mushrooms, while others won’t touch ‘em with a three-foot pole. You’re here because you fall into the former category (and we salute you), but one thing everyone can agree on is that soggy, moldy mushrooms are seriously gross. If you’re wondering how to tell if mushrooms are bad—you know, because they’re kind of an enigma—our handy guide is here to help. (Spoiler: If they’re wrinkly, slimy, smelly or getting darker, it’s bad news.)

Fresh mushrooms are plump with moisture and have smooth skin. The same cannot be said of fungi that’s been hanging out in your fridge for too long. In fact, wrinkled skin is a telltale sign that mushrooms have started to lose some of their moisture content and are thus past their prime.

There are many varieties of mushrooms, and not a single one of ‘em is supposed to be slimy. Indeed, mushrooms that have a slippery film are basically begging to be sent to the compost bin or trash can. Bottom line: We strongly suggest you take a hard pass on fungi that doesn’t feel dry to the touch, ‘cause it’s most certainly rotten.

When it comes to mushrooms, discoloration of any kind is a major red flag. Mushrooms that have developed dark splotches or turned a uniformly darker shade than before should be disposed of. Still, it’s worth noting that unwashed mushrooms often have dirt on their surface, so be sure to keep that in mind when you’re assessing the situation.

Mushrooms that have a strong or sour odor are (unsurprisingly) not safe for consumption. Yep, old mushrooms, like many other expired foods, can get rancid—and the nose always knows, friends. As such, it’s best to give your shrooms a sniff before sending them into the frying pan. Mushrooms that are mostly fragrance-free, save for a faint smell of earth and dirt, are safe to eat; anything more pungent is a strong indicator of spoilage.

Good news: Mushrooms have a relatively long lifespan when stored properly. Fresh, whole mushrooms can last for one to two weeks in the fridge, while sliced ones should be cooked and consumed within four to seven days. That said, the lifespan of store-bought mushrooms really depends on the condition they were in when you purchased them—something you’d be wise to assess straight away—as well as how you store them when you get home. (See below for best storage practice.)

Your instinct is to simply toss the plastic wrapped package in the fridge and call it a day—and that’s a-OK if mushrooms will be on the menu in the next few days. However, folks who want to extend the life of their fungi should know that the typical store packaging is not the way to go—namely because plastic wrap traps moisture and causes spoilage to happen faster. For this reason, the Mushroom Council recommends placing fresh, whole mushrooms in an open or perforated brown paper bag to allow for air circulation and discourage the development of mold and slimy stuff. Once you’ve relocated your mushrooms to a paper bag, simply stick them in the main compartment—not the crisper drawer—of the fridge and you’re good to go.