Like most vegetables bought in store, you should determine how long mushrooms can last based on the date of purchase.
Fresh whole mushrooms can be kept for up 10 days in the fridge, while fresh sliced mushrooms can last for up to 7 days. Cooked mushrooms can last for between 7 – 10 days in the fridge.
How to keeps mushrooms fresh
Here’s how to store mushrooms for maximum freshness.
If you store fresh mushrooms correctly, they'll stay good for up to 10 days.
It’s best to keep them whole and unpeeled and place the mushrooms in a zip-lock plastic bag before placing them in the fridge. This will stop them from getting slimy and going bad.
It’s also recommended that you keep mushrooms out of the crisper drawer, as it’s too moist an environment, away from foods with strong odours and don’t stack anything on top of the mushroom – they bruise easy!
If you’re planning to keep your mushrooms (whole or sliced) for longer than a week, it’s best to freeze them. Mushrooms can be kept frozen for 6-8 months but should be cooked first and placed in freezer safe containers or bags.
How long do cooked mushrooms last?
Properly stored cooked mushrooms can last for up to 10 days in the fridge.
According to Still Tasty, the best way to store cooked mushrooms is in a shallow airtight container or resealable plastic bag.
Bacteria can grow quickly in warm temperatures, so cooked mushrooms should be thrown out if they’ve been left out for more than 2 hours at room temperature.
If you want to keep the mushrooms for longer, just like fresh ones, it’s best to freeze them in covered airtight containers or plastic freezer bags.
Do mushrooms go off?
Just like most vegetables, mushrooms rot and grow bacteria if kept for too long, so yes, mushrooms can go bad.
Delishably reveals what are the signs that your mushrooms have gone off.
They're slimy. When mushrooms are slimy, they're not good to eat anymore. This could be from sitting in the fridge for too long. While they aren't definitively dangerous at this point, it's still a good common kitchen practice to toss them.
They have wrinkles. Sometimes mushrooms don't get slimy, but they do dry out and get wrinkles. While it's okay to dry out your mushrooms a little bit you don't want your mushrooms too wrinkly. So, if they're shrivelled up looking, it's a safer bet to toss rather than consume.
They're darker or have dark spots. Dark spots are a sign that they're starting to go bad. The best thing that you can do is to keep an eye on your mushrooms throughout the time they're in the fridge. If you see them getting darker or developing dark spots, it's time to use them or lose them.
They’re smelly. Your mushrooms shouldn't have a noticeable or strong odour. If you can smell them, they've gone bad.
Different types of mushrooms
The length of freshness can depend on the type of mushroom.
Cremini, portobello and white button mushrooms are the three most commonly consumed in the world. These mushrooms are actually all the same, although they look different, the vary appearance just depends on age.
White button mushrooms are the freshest and youngest, then cremini and portobellos have been left to mature for a long time.
Shiitake mushrooms, which are identified by their umbrella-shaped brown caps, differ in taste depending on their freshness – fresh shiitakes have a light woodsy flavour and aroma, while the dried versions are more intense.
What to do if you have eaten a mushroom you think has gone off
It is recommended that you only eat mushrooms you’ve bought from the supermarket, greengrocer or another reputable source.
Store-bought mushroom poisoning is highly unlikely, although eating a bad or spoiled mushroom could cause illness or an upset stomach. If they are left out for hours after cooking before placing them in the refrigerator, for instance, they could cause stomach problems once reheated.
To reduce the risks of illness, be sure to clean mushrooms well before eating and always store them in the fridge.
Be sure to visit your doctor or local GP if you are concerned. In any emergency, always call tripe zero (000).