Overall I prefer freeze-dried ingredients for long-term storage over dehydrated, but there are a few things i far prefer dehydrated. Mushrooms are one of those things. The act of dehydrating changes the structure of the mushroom. Freeze-drying mushrooms leaves them intact and raw, but when you dehydrate them, the heat slowly cooks them. It removes the water (of which mushrooms are high in) and in the end the umami flavor becomes dense.
You can dry whatever type mushroom you prefer, I usually do button or crimini mushrooms. My method is to go to a restaurant supply store and buy pre-sliced. I can get 2.5 pound containers for the same price as whole there, meaning one less thing to do. All I need to do is spread them on the dehydrator trays. It’s also a great project when a local grocery store runs some crazy deal like “10 for $1”. Buy when cheap, and preserve.
The main thing is: if you slice them, keep them the same size. Makes for easier drying.
Drying on the dehydrator.
I use a L’Equip dehydrator I have had for a very long time. I bought it in the mid 2000’s, and it’s been solid from day 1.
Spread your mushrooms on dehydrator trays, at first spread them out thin so the air can move around, to speed up the drying. I dry around 155° on my dehydrator. Every hour or two I move the trays so each tray gets a chance to be closest to the heat source. Keeps drying even that way. As they start to shrivel up and darken, you can condense the trays a bit. I find it takes around 12 hours or so to dry a load.
When the mushrooms are leathery dry – and you can’t feel any tacky spots – turn off, take the lid off, and let them air cool. Then pack them loosely into mason jars. 2.5 pounds fresh will fit into 2 quart mason jars.
Preserved for the season – and for winter dishes.
How to use?
When I making stews and stroganoff or similar, I place a cereal bowl full of them, cover with boiling water, and let hydrate for 15 or so minutes. I drain them, reserving the broth created. Saute the mushrooms as you would fresh ones. Use the broth in your recipe. It’s got an incredibly deep flavor and aroma. Unlike fresh mushrooms, the dried ones will have a pleasant chewy texture and never be slimy (my kids love the dried ones in meals, but complain about fresh).
The bonus? You know where your mushrooms come from. Most dried ones sold commercially are processed in China and can be years old. And often are rather dusty/dirty, so the soaking broth isn’t usable.