Last updated: August 22, 2026
Mushrooms go from firm to slimy in the crisper faster than almost anything else you bring home, and the two pound club store package is the usual trigger for learning to dry them. They also happen to be one of the easiest things a dehydrator does. No blanching, no peeling, no pretreatment argument, just a clean slice and a few hours of steady air.
The payoff is out of proportion to the work. Dried mushrooms take a fraction of the shelf space, they rehydrate into something closer to fresh than most dried vegetables manage, and the soaking liquid becomes stock. Grind a jar of them and you have a seasoning that improves nearly every braise you make all winter.
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Quick Answer
How do you dehydrate mushrooms?
- Brush or scrub them clean instead of soaking, because a waterlogged mushroom takes hours longer to dry.
- Colorado State University Extension lists slicing tender stalks about 1/4 inch thick, peeling and slicing large mushrooms, and leaving small ones whole.
- No blanching is listed for mushrooms. CSU Extension does list an optional dip in a solution of 1 teaspoon citric acid per quart of water for 10 minutes.
- CSU Extension lists a drying time of 8 to 12 hours and a dryness test of dry and leathery.
Bottom line: thin, even slices and a machine that moves air are the whole method.
Which Mushrooms Are Worth Drying
Almost all cultivated mushrooms dry well, but they do not all come back the same. Dense caps like cremini, portobello and shiitake rehydrate into something you would happily put in a stew. Delicate types such as oyster and enoki dry beautifully and then come back softer, which makes them better for soups and powders than for a pan sear.
Water content is the deciding factor. A mushroom that feels heavy for its size has more to lose and takes longer, and it also shrinks more dramatically, which surprises first timers who fill nine trays and end up with two jars.
A Word on Wild Mushrooms
Drying concentrates whatever is in the mushroom, and it does nothing to make a misidentified one safe. If you did not grow it or buy it, get the identification confirmed by someone qualified, such as a local mycological society or your state extension service, before it goes anywhere near the dehydrator.
Clean Without Soaking
Mushrooms are mostly water already, and a rinse adds more of it to a surface that absorbs readily. Brush the caps with a soft brush or wipe them with a barely damp cloth, and trim the dry, woody base of the stem. CSU Extension has you scrub them, discard tough woody stalks and slice tender stalks about 1/4 inch thick.
Grit in the gills is the one case where a quick rinse is worth the extra drying time. Rinse fast, drain on a towel, and let them air dry on the counter for a few minutes before slicing so the surface is not wet going onto the tray.
Slicing, and the Optional Citric Acid Dip
Even thickness beats any particular thickness. CSU Extension lists peeling and slicing large mushrooms and leaving small ones whole, with tender stalks cut about 1/4 inch. Whole small buttons work, they simply take the long end of the drying window because the moisture has to travel out through the cap.
The pretreatment is optional and cosmetic. CSU Extension lists a dip in a solution of 1 teaspoon citric acid per quart of water for 10 minutes, drained before drying, which helps keep pale mushrooms from browning. Skip it and you get a darker chip that tastes the same.
Load, Dry and Test
Lay the slices in a single layer with a little air between them, and resist stacking the overlap at the edges of the tray. CSU Extension lists 8 to 12 hours for mushrooms with a dryness test of dry and leathery. Where you land in that window depends on slice thickness, load size and how humid the kitchen is that day.
Test on cooled pieces, always. A warm slice feels flexible even when it is finished, so pull a few, let them sit on the counter for five minutes and then bend one. Leathery with no cool, damp core is the target for slices, while whole caps should feel light and rattle. Thin slices and torn oyster mushrooms drop through open grids, so mesh liners from our trays and sheets guide save the smaller pieces.
If you want even airflow without rotating trays
How the Common Types Behave
Different mushrooms earn their tray space in different ways. The table sorts the ones most home dryers actually buy in quantity, with the prep that suits each and the job it does best once it is back out of the jar.
| Type | Prep | How it dries | Best use later |
|---|---|---|---|
| Button and cremini | Brush, slice about 1/4 inch, optional citric acid dip | Even, predictable, shrinks hard | Stews, sauces, everyday cooking |
| Portobello | Remove stem, slice caps into planks | Slow, high water content | Braises and pasta sauces |
| Shiitake | Discard woody stems, dry caps whole or halved | Dries firm and keeps a strong aroma | Broths, ramen, rehydrated slices |
| Oyster | Tear rather than slice | Fast, becomes fragile and papery | Powder and soups |
Slicing thickness, the citric acid dip and the dryness test above follow the CSU Extension drying vegetables fact sheet, which lists no blanching step for mushrooms.
Conditioning and Storage
Conditioning catches the slice that finished the day looking dry and was not. CSU Extension has you place the cooled pieces loosely in large glass or plastic containers about two thirds full, hold them in a warm, dry, well ventilated place for four to 10 days, and stir or shake daily. Any condensation on the glass sends the batch back to the trays.
Then get the air out. CSU Extension notes properly stored dried vegetables keep well for six to 12 months, and mushrooms reabsorb moisture eagerly, which is why a sealed jar beats a bag clipped shut. Our guide to storing dehydrated food covers the options in order of cost.
If you want to pull the air out of the storage jar
Powder, and Getting Them Back
Mushroom powder is the reason to dry the ugly ones. Blitz fully dried slices in a spice grinder, sieve out the coarse bits, and keep the powder in a small jar away from steam. A spoonful thickens and deepens a pan sauce without adding liquid.
To rehydrate, cover the slices with hot water and let them sit until they are pliable, then lift them out rather than pouring, so the grit stays behind. Strain the soaking liquid and use it, because most of the flavor you paid for is dissolved in it.
Frequently Asked Questions
Do mushrooms need to be blanched before drying? No. The CSU Extension drying vegetables fact sheet lists no blanching for mushrooms, only cleaning, slicing and an optional citric acid dip. That is one reason they are a good first project on a new machine.
Should I wash mushrooms before dehydrating them? Brush or wipe if you can. Mushrooms absorb water quickly and a soaked cap adds hours to the drying time. Where grit in the gills makes a rinse unavoidable, drain and surface dry before slicing.
How thick should the slices be? CSU Extension lists tender stalks sliced about 1/4 inch, with large mushrooms peeled and sliced and small ones left whole. Consistency across the tray matters more than the exact number, because uneven slices finish at different times.
How long do dried mushrooms keep? CSU Extension states properly stored dried vegetables keep well for six to 12 months in cool, dark, dry conditions. Mushrooms that soften in the jar were either underdried or stored somewhere humid, and both are fixed by conditioning first.
Can I dry wild mushrooms I picked myself? Only ones whose identification has been confirmed by a qualified source such as a mycological society or your state extension service. Drying preserves a mushroom, it does not make an unsafe one safe.
The Bottom Line
Mushrooms are the low effort win of the dehydrating world: brush, slice evenly, dry to leathery in the 8 to 12 hour window CSU Extension lists, condition, then seal. Keep the soaking liquid, grind the broken pieces into powder, and the two pound package stops being a race against the crisper drawer. If you are choosing hardware, start with our food dehydrator buying guide, and read vertical against horizontal airflow before you commit, because tray to tray evenness is what decides whether small slices all finish together.