Dehydrating Mushrooms

I love mushrooms of all types and I particularly enjoy foraging for them. The problem is they just do not keep for very long in the fridge. With the effort needed to find them in the wild or the cost to buy them in the store so great I long ago started dehydrating them.

Baby Bella Whole

The nice bonus with drying mushrooms is that with some things dehydrating enhances the flavor, mushrooms are definitely in that category.

I recently bought a good deal of Baby Portabella mushrooms on sale for $0.99 a pound and thought I would do a separate small batch  to show the process of drying them as well as how much weight and volume they are reduced by for those new to dehydrating. I started with 150 grams of  small mushrooms that you see here on the scale for a nice even number.

Weight of just the caps
Baby Bella Stems
Stems cut in halves and quarters








I weighed the caps by themselves (above) just to see what percentage of the weight was lost by removing the stems, as many people throw the stems away. Even though the mushrooms were well trimmed as to the length of the stems, I was surprised to see that almost a third of the weight was lost.

Baby Bella Caps
Sliced mushroom caps spread out on dehydrator tray

After slicing the mushroom caps I spread them out on one tray and the stems on another. There is nothing fancy about the dehydrator I used, its only temperature control is actually just a vent that you can adjust as to how much air can rise up though the unit.

Mushroom caps and stems completely dry
Mushroom caps and stems completely dry

I let the mushrooms dry for about 36 hours at about 95 F. To check them for dryness just bend a few pieces to see if they will snap in half crisply. If they do they are dry enough to store in an airtight container such as glass canning jars. Just like storing other foods, it is best to keep them in a dark, dry, and cool place for maximum shelf life (maybe an unheated room/pantry or dry basement).

You will notice on the scale here that both the caps and stems together only weigh 10 grams now, or just a little over 6% of their original weight.

Just the dried stems
Just the dried stems

After weighing the stems by themselves we have some beginning and ending weights for each.                                           Fresh Caps                 107g Fresh Stems                 43g Dried Caps                      6g Dried Stems                   4g                                                         The caps lost 95% of their weight, and the stems lost 91% of their weight.

Baby Bella stems (left) and caps (right) in half pint jelly jars

Here you see them in 1/2 pint jelly jars, and I would estimate they lost about 65% of their original volume.

Ok we have dried mushrooms, now what do we do with them? I use them almost like fresh more often than not. I decide how much I need and let them soak in warm water for a half hour or so to reconstitute. I will use them this way in omelets, on cheese steak subs, and beef burritos or tacos.

If I am using them in a soup or a stew I do not bother to re-hydrate them. I just toss them in and let them re-hydrate while cooking. Speaking of which, never throw out the water you use when you re-hydrate your mushrooms. Dehydrated mushrooms make some of the best broth you have ever tasted! One of the things I like to make with the broth is french onion soup. Mushrooms in french onion soup? Yes indeed! I know that most recipes do not call for it, but mushroom broth is rich enough that you can actually cut the beef bullion almost in half for a french onion soup and not even notice it.

What about those stems? They are fine in most anything despite many throwing them away. Do you think all those little cubes in Campbell’s cream of mushroom soup are premium mushroom caps? There are dishes that you do not want meaty chunks of mushroom in however, but you do want that mushroom flavor. As an example I like making my gravies that way.

The solution I use is to make my stems into mushroom powder for those recipes. Being so brittle the stems readily grind to a fine powder in a mortar and pestle. I then run them through a fine screen sieve to be sure I did not miss any larger pieces. If you do not have a mortar, they crumble rather well with a little help through a screen. For those of you that like electric, one of those little 1 cup food processors is what I use for herbs and seasonings as they clean out so easily.

Mortar and Pestle

For a short video of making a powder out of the stems you can see it here: Making mushroom powder with a mortar and pestle

I now have a nice supply of healthy mushrooms for all those hearty soups, stews, and roasts I will be making this winter.

Thanks for visiting!
For more information and discussion join us here
Forum Topic: Dehydrating Mushrooms