Dried mushrooms are easy to make at home and allow you to preserve their flavor year-round. Although possibly the best way to dry mushrooms is in a dehydrator, you can get very good results using your home oven.
Fresh, foraged mushrooms are seasonal, and when you bring home a bounty, you don't want them to go to waste. You may also want to preserve your store-bought mushrooms that you bought on sale or just didn't get around to using all at once.
Most mushrooms dry beautifully. They even gain flavor from the process of drying. When you rehydrate them months later, their texture is almost identical to fresh mushrooms. Dried mushrooms can be stored for at least a year. Here is how to dry mushrooms in the oven. Note that you'll need baking sheets and jars for this process.
1. Preheat Your Oven
Preheat the oven to 150F/65C.
2. Clean the Mushrooms
Wash the mushrooms in water. It's a myth that they soak up lots of water. You will want to clean them well by scrubbing gently with a vegetable or mushroom brush as necessary. Washing them will help get all of the dirt out of nooks and crannies. If you prefer, you can slice them first and then wash them.
3. Slice the Mushrooms
Slice the mushrooms 1/8 to 1/4-inch thick. Thicker slices will take longer to dry. That's more of a consideration when using your oven instead of a dehydrator, as you'll be tying it up for hours.
4. Blot and Arrange the Mushrooms
Spread the sliced mushrooms on a clean dishtowel. Loosely roll up the towel and squeeze gently to remove any surface moisture.
Arrange the cleaned, sliced mushrooms on the baking sheet, making sure that none of the pieces touch or overlap.
5. Drying in the Oven
Place the baking sheet in the oven and leave for 1 hour.
Turn the mushroom slices over and return to the oven for another hour.
6. Check for Dryness After Two Hours
Take them out of the oven and let them cool before checking to see if they are crispy-dry. The cooling off period is essential because, like cookies coming out of the oven, they will crisp up considerably as they cool.
If the mushrooms are not completely dry, turn them over again and return them to the oven for 30 more minutes. Keep turning them over and checking for dryness every 1/2 hour.
7. Cool Dried Mushrooms and Place in Jars
Allow the dried mushrooms to cool completely before transferring them to glass jars. Cover tightly with lids. Label the jars as to the variety of mushroom and the date that you dried them. That will help your memory in coming months, and you can be sure to use them within a year. Store the jars away from direct light or heat.
Rehydrating Your Dried Mushrooms
To use dehydrated mushrooms, pour boiling water over them in a heat-proof bowl. Let them soak for 20 to 30 minutes. When you drain them, save the liquid as it will give a rich flavor to soup stocks and sauces. Use the rehydrated mushrooms as you would fresh mushrooms.