Mushrooms that would love to be dehydrated L t R: Porcini, Black Trumpets, Lobsters, Porcini, Morels (bottom).
Nature’s bounty can come in giant waves and intense fruitings throughout the year. If you’re a wild mushroom hunter, you’ll quickly realize you need a plan to figure out what you’re going to do with all of your free food. One of the easiest ways of preserving food, especially mushrooms, is drying / dehydrating them.
These morels will go in the dehydrator as soon as I get home. Note the fungus growing on them. After dehydrating, they should be fine. I trim off the mold with a paring knife before drying.
I’ve tried to dry and preserve almost every mushroom I’ve come across, and I was the point man for drying and preserving the hundreds of pounds of wild mushrooms that came through the door for a professional restaurant years ago.
Drying mushrooms at home isn’t as serious as it is in a restaurant, where I’ve seen 30, 40 or even 100 lbs dealt with at a single time, but a few little tips and tricks can save you from possible heartbreak in the event you were out on a very hot or wet day when picking. Properly dried, your mushrooms will last, literally, for years to come with minimal loss of flavor. Here are some things I find helpful, and some Q and A style tips I’ve gotten from readers.
My Tips on Drying Wild Mushrooms
Clean and separate your mushrooms
You don’t *have to* clean them, but it’s a good idea to brush the mushrooms well before drying, especially if you’re going to powder them for using as a seasoning, or for crusting meat, etc.
Ideally, you’ll pick clean mushrooms in the field. It can be tempting to dry dirty mushrooms thinking that dirt will wash off, but rainy, muddy mushrooms may not rehydrate clean. Brush and inspect the mushrooms in the field, trim off dirty parts with a knife and discard, and then give them another once over at home, as much as possible without washing them. The cleaner the mushrooms are that go into your bag, the less work you have to do later.
If I have some suspect dirty mushrooms, or ones I want to use for a different purpose (really small morels make better soup garnish than larger ones, for example) I like to separate them out before I dry them.
Space them out evenly in the dehydrator
With delicate mushrooms like slippery jacks, or mushrooms picked in the later stage of their life cycle, the heat created by dehydrators can actually speed up the decomposition process, especially if they do not have proper breathing room. When I first started picking I once opened up the door of my dehydrator and had to scrape liquified slippery jacks off of the bottom, it wasn’t fun, and the smell was even worse than the work.
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- The proper drying technique, spaced out your mushrooms will dry quickly.
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- Improper drying technique is when the mushrooms touch and overlap
Dry mushrooms as soon as you can
This ensures that your mushrooms were dried in peak condition, and will rehydrate in peak condition.
What temperature do you set the dehydrator to?
A certain amount of heat can help develop good flavors in your dried mushrooms, allowing toasty aromas to develop. If your dehydrator has a setting, 135 F, or something warm enough to toast them is good. If your dehydrator doesn’t have a specific heat setting, you can always toast the mushrooms a bit before cooking with them in a pan or in the oven. You can also fry them after rehydrating.
For example. On the left: trumpets I let sit out too long before drying, which putrify while dehydrating. On the right: properly dried black trumpets.
Don’t dry wet mushrooms
If your mushrooms are wet from rain or warm from being in a vehicle, before even thinking about processing, cooking, or cleaning them, lay them out comfortably on a cookie sheet and refrigerate them immediately, covered in a slightly moist towel or rag. They need to aerate, cool quickly, and breathe to retain their shelf life. Once they’re cooled, you will have the best success drying them.
Morels left to right: fresh, morels that went foul while drying, and properly dried.
Thinly slice your mushrooms
Thinly sliced mushrooms will dehyrate faster, mushrooms cut too thick can be tough after rehydrating. I do not dry whole mushrooms, unless they’re hollow, like black trumpets, morels or yellowfeet. I don’t reccomend drying mushrooms whole, since they can be very tough.
Drying is a great way to use insect damaged mushrooms
After they’re dehydrated, they can be ground into powders that will create stocks, rich compound butters, rubs and other things.
How long does it take?
This varies between species of mushrooms. Black trumpets will usually dehydrate themselves where I live in Minnesota, if I leave them on the counter. Basically, the thicker the mushroom, the more water it has, and the longer it will take to dry. Boletes take the longest by far, but I’ve never really had any sliced mushroom take longer than 48 hours to dry.
How dry should they be?
The answer is cracker-dry. Properly dried shrooms should almost be brittle, if there are any in your dried collection that still seems to have soft spots, either leave the top of the container you are going to store them open for a while so they continue to aerate, or dehydrate for another 24 hours.
Drying wild mushrooms without a dehydrator
You don’t have to have a dehydrator, but they’re nice to have. People have been drying mushrooms for eons without a dehydrator, here’s a few ways you might do it, and a couple troubleshooting tips.
- Slice the mushrooms as thin as possible
- Sliced mushrooms can be threaded with a needle and string, then you can hang them up and let them air dry outside, this is one of the oldest techniques.
- Blow a fan on the mushrooms constantly, it may take days for them to be completely dry.
- Laying sliced mushrooms on screens outside or in a dry place
- If the mushrooms feel even the slightest bit moist, leave them out for a while longer.
- Putting the mushrooms on a cooling rack in an oven on the warm setting, as long as it isn’t hot enough to cook them works too, I like to keep the oven cracked open a bit though.
Re-Hydrating and Cooking
This wouldn’t be complete without a mention of how to rehydrate mushrooms after they’re dried. You may not think about it, and I definitely didn’t at first, but the amount of time the mushrooms are rehydrated is very, very important when cooking with them. I like to rehydrate mushrooms just as long as they need, and no longer, typically 15-30 minutes is fine, especially when using a wet preparation.
Can you leave dried mushrooms in water for too long?
Yes. The flavor of mushrooms, as a general rule is very water soluble. When dried mushrooms contacts water, a little of the soul of the mushroom goes into it, and the amount of mushroom flavor contained in the water increases the longer the mushrooms are soaking. As well, over-rehydrated mushrooms, especially boletes, can have a kind of unpleasant, saturated texture, on the side of slugs.
Depending on what you’re doing, it might not be an issue, for example, making a cream soup where the mushrooms will be pureed with their juice won’t make a difference, but rehydrating mushrooms to saute with some fresh ones and eat on some fresh arugula might suffer a bit.
Cooking dried mushrooms without rehydrating
As long as your mushrooms were clean, grinding wild mushrooms into powder is a great use for them, especially for things like porcini that have been sampled by bugs. Here’s a few examples:
- Morel crusted venison tenderloin
- Lobster mushroom seasoning
- Slippery jack-coffee rub
- Nettle ravioli with dried lactarius broth
Dried Mushroom Recipes
Now that you’ve brushed up on the basics, browse my selection recipes geared for using up your dried mushroom stash.
Dried Mushroom Recipes
hello, thank you for your description of Pluteus/Fawn. I was wondering your tips on drying mushrooms without a dehydrator. thanks!
I made some changes to the dried mushroom post for you. You can set them up on screens, or really any way you want as long as they are getting good air flow. Blow a fan on them continuously until they are cracker dry.
SO sadly my mushrooms look like the middle ones, and I’m not sure why they dry dark and small like that. I brought them home, left them in the fridge overnight in a paper sack, and put them on the dehydrator at a low heat setting. The ones I started drying outside first, then put in the dehydrator turned out fine. Live and learn, but when I borrowed a friend’s dehydrator they never turned out like that! Any ideas on what I’m doing wrong? My dehydrator has heat settings from 90-145 and I’ve tried various setting with the same results. ugh!
The blackening is from the morels wilting and beginning the decomposition process as opposed to the drying process, they end up drying anyway, but their flavor won’t be as good, and it’s just not good practice. A sure fire way to fix it is to separate out morels you want to dry or are damaged immediately when you return home from hunting. You want the absolute lowest heat setting available on the dehydrator too. I’ve also found that some dehydrators are just too hot, and that they will do what you describe to mushrooms most of the time, especially with species like slippery jacks or short lived boletes. Opening the door while they’re dehydrating can help too. Also I use a harvest maid dehydrator, they’re tanks, but work really great. Good luck.
My first batch of morels in the dehydrator turned out just fine. The second batch however turned black and shriveled, like the middle picture. The second batch was soaked in salt water like so many other site suggested. Obviously lesson learned, but I guess my question is are the still ok to eat. How do you know when they have to be thrown away? They smell fine, like mushrooms.
They’re ok, just salted.
I have Puffball mushrooms and I ground the up “fine” in a food processor. I put the ground mushroom in the oven and dried it into a very dry crumb. In the process of drying the ground white mushroom turned brown…..I probably had the oven a little warm. The whole process took four hours and the end product is a crisp tray of ground mushrooms which I will now grind again and add to soup.
I worried that the dried mushroom turned brown in the drying process. Do you think it is safe to eat?
Thanks
As long as it is totally dry, I suspect the powder will be fine. If it smells putrid or rotten, it is no good.
Here’s a challenge: How did traditional (pre-modern) peoples dry mushrooms? Sun drying would be my first guess. But if mushrooms grow during wet, rainy, and humid times of the year, how did they find enough sun or dry air?
My daughter is in southern Africa with the Peace Corps. She says it is mushroom season, but because it is the wet season it is too cloudy and humid to dry them naturally. And, of course, she doesn’t have any electricity for a dehydrator or oven. Possibly hanging them on string near the cook fire might be dry enough? Or instead of drying, cook slowly in oil until all moisture is gone and they will keep safely at room temperature submerged in the oil?
My guess would be fire.
No matter how I dry morels they shrink significantly. I have bought dried morels in the store and they appear to be full size. What am I doing wrong?
You could be drying them with heat. You want to dessicate them, or dry with only cool air, it takes more time, but the results are worth it. As long as the mushrooms are being dried without heat, there should be no issue with “over-dehydrating either”. Another possibility is that the mushrooms were wet when you started to dry them, which can make them go bad, shrink, and blacken as they dry.
I’ve gotten sick before from eating mushrooms we ate without cleaning properly. I’m wondering, can I just slice them in half ( BTW I’m talking about morels) and lay them on my sun drying screens then shake off anything after the fact or do I need to somehow debug them first?
I’m wondering because I know that they look perfect if you just take them from the truck and throw them on the screen LOL but I don’t know if that is safe to eat afterwards
If you got sick from mushrooms before I’d wager it wasn’t because they were unclean. You likely have an allergy or they weren’t cooked long enough. I have seen the allergy happen more frequently with natural black morels (not burn morels).
Hi. This is my first time dehydrating morels. I kept them overnight in the fridge, and then put them in the dehydrator on low heat. I dried them tell they were hard and crunchy. I sealed them in packages using a food saver. The next day, there was air in the sealed packages and now the mushrooms are moist and kind of squishy. I think they are ruined. Any suggestions?
If they’re moist they’ve re-hydrated somehow. Throw them away.
Thanks! That’s what I figured, as well.
I have some huge oyster mushrooms, can I string them whole or should I slice them first. I live in the Eastern Townships, QC. I sure hope they are oyster muchrooms!
Wow great post. Just chimming in from our wild mushroom operation. In May/June morels season in BC, Canada we sun dry for the first day which gets them 1/2 dry. On the second day the morels go into our portable wood fired dehydrator with lots of fan power. An oven won’t work for lack of air circulation. Air circulation is key, heat is secondary importance but we do use lotsa heat. The first few hours are at 100F while they are still moist and we finish them off at 140F. Ive dried lots of ways and using this heat does not diminish quality in morels. I surveyed 1/2 dozen fellow morel buyers and they also dry on site at up to 140F. We run a fall mushrooms foraging camp and I find that people chronically underdry their mushrooms. Sometimes I notice hard cassing occurs when too much heat it used too soon and the drying process is not completed. Then a moist center remains hidden. One way to get around this is to break some pieces, like Allen said, they should crack dry. If youre not sure, take all your freshly dried mushrooms and place them in a container. Wait 24hrs or overnight and check them again. Sometimes theres a thicker one thats wet and with time will spread to the other dry ones making them all a little flexible. Nows your chance to dehydrate them more before they mold or rot. Once dry though…. you’re golden 🙂 Well, happy foraging and eating!
Hi, I recently dried some hen of the woods. They were cracker dry, and I placed them in a freezer bag and pressed the air out. But when I checked on them two days later they were pliable and not crispy. Was it moisture in the air or did they somehow retain moisture after drying? I am pretty sure my bag is air tight.
Most importantly, will they be ok?
If you have any doubt, leave the bag open to allow air to escape, or put them back in the dehydrator for a while. Better safe than sorry.
If you’re worried, put them back in the de-hydrator. I tend to leave mushrooms in the dehydrator for a day or two after they’re done de-hydrating, often because I’m lazy and forget about them, but i’ve never really had any go bad in numbers. As long as they’re cracker dry, they should be good, just make sure no moisture gets in the bag. Keep an eye on them and you’ll be fine.
I’m really glad I found your blog. I’m still fairly new to foraging and learning what to look for and then what to do with it. Thanks for all the great tips!
Hi, do matsutake mushrooms dry well? I just foraged about 15lbs and need to preserve them.
They dry ok, but not as good as boletes, trumpets or morels. Try chopping them up putting them in a congee.
For morels, you should cut a thin slice off at the bottom of the mushroom stem and cut the mushrooms in half and make sure they are all clean you can now slightly rinse it with cool water to remove the dirt.
I prefer to leave them whole for the look but, you can definitely do that.
My dehydrator does not have a thermostat so I measured the temp of it. It was 160 degrees. Way to hot! No wonder some of my mushrooms did not taste very good rehydrated. Lilac and noble boletes were delicious but bicolors and various Suillus species were awful. I’ll definitely be looking into getting another dehydrator or using another method.
I do have a question though. What is the best way to preserve lactarius species? I’ve tried freezing and dehydrating indigos and leatherbacks (volemus) and neither turned out too well. But again, my dehydrator is way to hot.
Hi Joseph, as far as Lactifluus go, I like to prepare them in conserve, marinate or pickle, since it keeps their texture. Never heard of the common name leatherback for L. Volemus either, so thanks for that. I have a recipe for wild mushroom conserve on the website you should definitely bookmark for those species. There’s a milk cap mushroom preserve in oil too, where they’re blanched in a seasoned vinegar solution that keeps the color of L. indigo, if you’re interested in keeping them blue, I think it’s kind of fun.
Thank you so much! I saved both recipes and will try them this year, especially if the indigos hit like they did this past year. Two questions though. In the fridge, how long would each of these recipes keep the mushrooms good for, and what can you do with them once preserved? Eat them as is or could you still cook them like a sauté or in other recipes? Thank you so much for your advice.
Hello Alan,
Great post. Was curious, do you clean your morels at all before dehydrating? Let us know.
Thanks.
John
No, generally I don’t. when I rehydrate the morels, they get soaked in water, then agitated to remove grit, then I strain the liquid and recombine the two. The process is the same for all dried mushrooms, and come to think of it, your question is a great one, and I’m going to amend the post to include it. Thanks.
Great! Glad we could help. That answers most of our questions. One more, do you ever encounter grit after the rehydration and recombining process?
Just read your updated post. Thanks for the info.
If my dehydrator is to hot (120-130) can I leave the cover off while dehydrating?
Yes.
if dehydrator is to hot can I leave the cover off?? If not what is the best way to cool your dehydrator down ? Ill I have is an on and off button, not way to turn heat down.
Yes leave the cover off, totally fine, I often leave the door cracked on mine.
Super helpful, Alan, tx. Finding kilos of ceps daily right now in Sweden, a bumper year. Trying all possible methods of preserving, as it’s way too much to eat. Have given away several kilos!
Thanks, enjoy your Boletes!
I found 8 big hen of the wood they very in size the largest one being 67lbs any tips on how I should save them please help me I don’t want them going to waste
Pickle them, make jerky, duxelles, etc.
Thanks for all the great info ! I just dehydrated a bunch of morels for the first time, until they were very brittle. A few days later, I noticed mold growing on the biggest ones – the smaller ones, in different jars, seem fine.
Is there anything I can do with those that have started to mold, or are they dangerous to eat ? Most have from about !/3 covered in mold to just a light sprinkling.
Even though they’re probably safe after cooking, I would toss them as mold can affect the flavor.
I kept some chicken of the woods and oysters in a paper bag in the fridge and they got dark and dried out. Can I use them? They’re not slimy or smelly… Thanks!
They’re probably dried, continue drying them out, then put them in soup or something.
i found a fair amount of naturally dried hens,about 10#s,what’s the best way to rehydrate them? the base is still moist. Will the frods hydrate from the bottom if soaked?
I wouldn’t pick old mushrooms like that, skip them and find some good ones.
Do cauliflower mushrooms dehydrate well? I would also appreciate it if you could give me some tips on temperature and time in the dehydrator.
Cauliflower mushrooms are sold regularly in Asian markets so I assume they’ll rehydrate well, I haven’t tried them specifically yet.