Best way to preserve mushrooms until dehydration?

My belle has a real eye for mushrooms. She can spot them in almost any environment. She recently found a crazy bounty of Agaricus campestris in a spot in Seattle, and while walking back from it with a bag of several pounds in hand, found another spot. The mushrooms were all at peak and couldn't grow even another day.

Great as this is, we can't possibly eat fresh or even give all these away, and I'm 90 minutes from her in the woods. Because I am supposedly better situated to find mushrooms, EYE have the Excalibur dehydrator...and I won't be seeing her for 3 days.

So what is the best way to preserve mushrooms until you can dry them? The fridge dries them out, makes them smell funny and gives the fly larvae a chance to hatch, but the freezer did something weird to the test batch we froze (as freezers do) and I'm not sure they'll dehydrate well. And don't say the oven, she doesn't have one. As far as I can tell it's between the fridge and the freezer!

Have you thought about the North side of the house in shade, on a table, away from critters? That certainly won't dry them out quickly, not with the weather we've been having.
John S
PDX OR

i ve read about slicing them up and using a needle to put them on a thread. then put these threads horicontally and dry them.

maybe one could use an electric fan to help. could you do some research/reading on that method?

after that, finish them in the dehydrator.

I commonly keep mushrooms for up to a week in the fridge.  They can dry out a bit but if you keep them in a cotton bag it makes for a nice balance between letting them breath and keeping them a bit moist.  I have thin cotton produce bags I use.   Paper bags work too but not as well as the cotton.  I've never had a problem with them taking on taste or odors from the fridge but I image it might depend on what else is in the fridge.  

As for the larvae...if they are have a lot don't think I'd try to keep them for very long.  The sooner you process them the better.  

I'd say in your case to freeze them.  But as you likely found before they don't freeze well on their own.  You have to remove as much moisture as possible. I've tried a few ways and best I've found is the dry sautée them.  I slice them thin and sautee is a hot dry pan, no oil, butter, or anything else at 1st.  I'm always surprised by how much moisture comes out of them.  They're usually swimming in liquid at first.  Keep stirring until all the moisture is gone.  Some people then freeze them at this stage.  I like to add a few tablespoons of oil.  Enough to add a thin coating to the mushrooms.  I feel like it help preserve them and prevent freezer burn.  I then spread them out on wax paper covered baking sheets and freeze them.  Once frozen you can remove them from the sheets...I usually break them up into chuncks and put them in freezer bags.  If I think I'll be keeping them longer term they get vacuum sealed.  Then when I'm ready to use them I can just pull a chunk or two out of the freezer and add them to whatever I'm making.  

Another option is to pickle them.  I've tried this once (with store bought button mushrooms) and they actually turned out better then I expected.  I just haven't found that many uses for pickled mushrooms other then just eating them and I tend to like to cook with my wild mushrooms so I haven't done it again.  There is also some issue with using wild mushrooms if they are not going to be cooked.  I think if you then can the pickles (and you can water bath can pickles because of the high acid levels) the heat you expose them to in the process substitutes for cooking but proceed at your own risk..or level of comfort with risky kitchen behavior.

Another option is to can them without the pickling.  I think Agaricus would hold up well to canning.  But you have to use a pressure canner for mushrooms so this is only an option if you have one or can find access to one.  

Another way to use up/preserve a mushroom windfall is the make broth from them.  A nice thick mushroom broth makes a lovely soup base, a great addition to many sauces, and add a wonderful flavor when use to cook grains like rice or barley.  The broth can be frozen or canned (again you'd need a pressure canner) for future use.

Thank you all.

Tobias, that is a really good point...the last time we dried mushrooms in her basement apt with a fan, they were not suspended on a thread, and the part resting on a surface got gross. We dehydrator'd them anyway but not sure how that gross fermenty browning will affect their taste.

John, trust me, the slugs would find them there! These are slugs that will eat paper if nothing else is around. Slugs get in the open windows even.

Chris, that is a great array of solutions. Dry sauteeing especially. It made me think of putting them in an iron skillet but up on a platform, maybe a terra cotta plate or a grill, to sweat them dry perhaps. We are mushrooming aggressively right now as the season nears its end, so I'm sure we'll have recourse to all these methods.

Get screening to slice them on and let air flow all around them and then a mesh to keep the bugs off them and dry them in the sun. They are AMAZING at absorbing huge quantities of vitamin D3, and when completely dry, and I mean completely, put them in mason jars and they will (could technically) last for years. But you'll re-hydrate them, eat them as is all leathery, put them in soups and stews.

Make sure when collecting them that you brush off or cut off the spores and leave them, just remember where, for next year. They were happy in that location so let them come back there again next year.

Thanks Lee. I slice them thin enough to dry til they're brittle; Excalibur trays accommodate 1" width well.

Good point about the spores. I break up and tamp in pieces of suboptimal mushrooms I pick. I am usually foraging on land that resembles the land I occupy, so I also take the stem butts and trimmings and distribute them as a spore slurry or pieces. A lot of Zeller's boletes have appeared this way, especially around areas where I process mushrooms.

Lee Gee wrote:They are AMAZING at absorbing huge quantities of vitamin D3

Perhaps you're thinking of D2. Mushrooms contain the vitamin D precursor compounds ergocalciferol and dihydroergosterol, which vitamins D2 and D4 are derived from, respectively. D3 is derived from animal sources and I'm not aware of mushrooms containing dehydrocholesterol, the precursor to D3.