How Long Do Mushrooms Last? Can They Go Bad?
Mushrooms are nutritionally rich, packed with B vitamins which contribute to energy levels and brain function. They also taste great, and whether it’s your fry-up at brunch or a sophisticated risotto for your evening meal it’s always a good time for mushrooms.
But mushrooms are a divisive foodstuff and many people have questions about how to use them. Mushrooms are fungi, and this puts them in a unique category amongst our foodstuffs – neither plant nor animal!
So if you have some questions about using mushrooms in the kitchen I don’t blame you.
The last thing you want to be serving up is a slimy mushroom that’s past its best. So let’s learn about how long mushrooms last, and how to tell if they’ve gone bad. Mushrooms are a fantastically diverse ingredient and we’ll explore the differences between popular types of mushroom, as well as dried options for your store cupboard.
And once you’ve mastered the mighty fungus in your cooking, you won’t have mushroom for dessert!
The Kinds of Mushrooms
Whether you’ve taken a stroll through a lush wet woodland or just down the vegetable aisle at your local grocery store, you’ll know that mushrooms come in all shapes and sizes! These are some of the common mushrooms that you’ll encounter.
White Button and Chestnut Mushrooms
These are the most common mushrooms and possess that mild nutty flavour you’re likely to be familiar with. Perfect in fry ups, stir fries, risottos, soups and stews, button mushrooms are incredibly versatile and if you’re a mushroom fan these should be a staple in your kitchen.
Portobello mushrooms, also known as field mushrooms or open caps, are mature mushrooms that have aged like a fine wine and bloomed into magnificent broad-capped specimens. Thanks to their size, portobello mushrooms are perfect for stuffing with tasty ingredients and can even take the place of the bread in your burger if you’re looking to cut out the carbs!
Chanterelles are a delicacy rarely found in your regular supermarket, but if you frequent upmarket delis you might come across these on the shelves. They are challenging to cultivate but grow freely in the wild, so mushroom foragers often stumble upon chanterelles. However, foraging mushrooms is a dangerous business as there are many toxic types out there. Stick to the shelves for your mushrooms unless you’re with a mycological master!
If you’re big into Asian flavours then you might encounter shiitake mushrooms or enoki mushrooms on a regular basis. A shiitake mushroom is reminiscent of the western chestnut mushroom but possesses a strong savoury flavour. Enoki mushrooms are distinctive, with long stems and small white caps and these sturdy mushrooms hold up well in soups and salads.
Many mushrooms, such as portobellos, chestnut and enoki, taste best when they’re used fresh. However, other strong flavoured mushrooms can be dried and still pack a punch, whether rehydrated in a soup or stew or used to beef up a tasty sauce. Dried shiitakes or chanterelles will last longer in your store cupboard and will still come out tasting great!
Do Mushrooms Go Bad?
Bad news mushroom fans – your mushrooms have a finite lifespan. All mushrooms will go bad eventually.
Most fresh mushrooms, if they’re stored correctly, will last for up to two weeks in your kitchen before time starts slipping away. Shiitake mushrooms, enokis and the common white button mushroom will last around fourteen days in your fridge.
Fresh portobello mushrooms are a different story, however. Because these mushrooms have been allowed to age and bloom into burger-bun proportions, they tend to be packed and shelved closer to the end of their lifespan. A portobello mushroom should be used within two or three days of purchase. Fortunately, they’re so tasty that you won’t want to wait.
Dried mushrooms last much longer than fresh mushrooms – that’s a natural result of the dehydration process, as it’s the water content of fresh food that enables rotting to take place.
Dried mushrooms will last for up to a year if they’re stored in an airtight container. And even after a year, if you stumble upon some long-forgotten dried mushrooms at the back of your cupboard they might still be good to use.
Because fresh mushrooms can go bad at different rates, and because dried mushrooms can last longer than a year, using hard-and-fast rules for your mushrooms use-by dates might result in you cooking up a bad ‘shroom, or throwing out some perfectly edible dried shiitakes.
Fortunately, there are some tell-tale signs that will inform you about a mushroom’s freshness. Let’s find out how to tell if a mushroom is bad!
How to Tell If A Mushroom Has Gone Bad
If you’re going to maximize your mushroom’s lifespan then you need to know the sure signs of a mouldy mushroom.
Some of these are obvious hints, whilst others are a little more subtle. Nobody likes wasting food so let’s find out how to tell if a mushroom is bad.
First of all, we recommend using caution with mushrooms that are on the turn. One bad mushroom can ruin your masterpiece of a meal – once mushrooms are off they quickly develop an unpleasant flavour. If your mushrooms have been around for more than two weeks, play it safe and toss them in the trash.
The first sign of a bad mushroom is a slimy cap. Sometimes this will be detectable from a visual inspection and any mushroom that develops a sheen on the cap should be treated with suspicion, but the best way to spot the slime is by a simple touch test. A slimy-capped mushroom might not be dangerous to your health, but at the very least flavour will have been compromised. Chefs with high standards won’t let a shiny ‘shroom anywhere near their creations.
Whilst a slimy mushroom can be the product of too much moisture seeping out, some mushrooms dry out as they age – even when stored correctly. If a mushroom is wrinkling across its cap, this is a sure sign that your mushroom has gone bad. A mushroom’s cap should be smooth – if it’s wrinkly, toss it!
- Dark Spots
As mushrooms begin to go bad, their color will darken and the caps will begin to develop splotchy dark patches. On light-colored mushrooms such as white buttons or enokis these patches are obvious, but even on darker mushrooms such as chestnuts and portobellos these spots will appear black on the brown caps.
- The Smell
Fresh mushrooms usually have a very mild smell, and only once a mushroom is chopped or split open will its full scent be revealed. This means that any mushrooms developing a strong odor are very likely to be going bad.
With slime, wrinkling and a potent odor being the main signs that a mushroom has gone bad, you can use touch, sight and smell to assess whether a mushroom has gone bad.
- Dried Mushrooms
Dried mushrooms will last much longer than fresh mushrooms and can be reliable up to a year as long as they’re in an airtight container. Contrarily to fresh mushrooms, the smell of a dried mushroom will lose its potency as they go bad. Give your dried mushrooms a sniff and put trust in your senses.
How to Store Mushrooms
Mushroom storage can be a slippery business, but we’ve got some tricks up our sleeve to maximize your mushroom’s lifespan…
Fresh mushrooms can be up to 92% water, so they produce a lot of moisture! Moisture also produces ideal conditions for foods to go bad, so managing the moisture of a mushroom is essential to getting a long life out of your fresh mushrooms.
- Room to Breath
Letting your mushrooms breath allows this moisture to escape before it accelerates the aging of your mushrooms. Rather than smothering your mushrooms in an airtight container, try keeping them in a paper bag loosely rolled up. This allows for moisture to escape so your mushrooms won’t develop the dreaded slime.
- Manage Moisture
If you’re keeping your mushrooms in a plastic bag, then you’ll need another way to deal with the moisture that emanates from your mushrooms. Lining the plastic bag with paper towels allows the moisture to be absorbed – just remember to change the towels on a regular basis, so that the moisture doesn’t build up.
Can You Freeze Mushrooms?
Because fresh mushrooms are mostly water, they won’t freeze well – the process of freezing and thawing a mushroom will leave you with a soggy mess! If you need to freeze your mushrooms then cooking them first will rid them of this water content – you can then pack them into a freezer bag for later use.
What to do with Old Mushrooms
When the clock starts ticking on your fresh mushrooms it’s time to get cooking. Fortunately, mushrooms are so versatile that you have almost endless options!
Delicious mushroom soup can be whipped up on the hob in under an hour and will last for months in the fridge!
Even quicker is a mushroom pâté. Blitzed in the blender with some cream cheese, herbs and olive oil, this posh pâté goes great on toast, and can be frozen in an airtight container until you need a midnight snack!
From Asian to Italian cuisine, mushrooms are used across the world. You wouldn’t want to let any of this delicious ingredient go to waste. Bon appétit!