Dehydrating mushrooms in a dehydrator is a great way to preserve an abundance of mushrooms. You can use this method to make sure that the store-bought mushrooms in your refrigerator do not spoil before you get around to eating them.
Do not bother dehydrating mushrooms that you think are on their way to going bad. Signs that your mushrooms have started decomposing include slime accumulating on the surface, wrinkly, shriveled up mushrooms, mushrooms that get darker or get dark spots, or you notice any kind of bad odor coming from the mushrooms.
About Dehydrating Mushrooms in a Dehydrator
Most mushrooms dry beautifully, not only retaining but even gaining flavor in the process. When rehydrated in hot water, the texture is almost identical to that of fresh mushrooms. Dried mushrooms can be stored for at least a year.
Although mushrooms can be dried in the oven, you get the best results if you use a dehydrator following this simple method.
Cleaning and Slicing Mushrooms
First, you need to clean the mushrooms. Contrary to culinary myth, raw mushrooms do not soak up lots of water during a quick rinse. Do not skip washing them in water. Try to get all the dirt off the mushrooms with a vegetable or mushroom brush.
A thorough cleaning makes your cooking prep much easier, especially with mushroom types that have lots of nooks and crannies, such as maitake mushrooms.
Depending on which is easiest for the shape of the mushrooms, either clean them whole and then slice them or vice versa. It is acceptable to slice them first and then clean them if that seems easiest.
Slice the mushrooms into pieces that are between 1/4 to 1/2 inch thick. The thicker the slices, the longer it will take to dry, so consider this when you are slicing. Your choice of cut may depend on how you plan to use them later. If you like thick mushroom pieces in your dishes, slice them thicker.
Using the Dehydrator
Arrange the cleaned, sliced mushrooms on the dehydrator trays, making sure that none of the pieces touch or overlap. This allows the best airflow around them, and they will dry faster and more evenly. If they touch or overlap, some areas may retain some moisture.
Dry the sliced mushrooms at 110 F until the pieces are crispy dry (or follow specific instructions that come with your dehydrator). This process takes 4 to 6 hours for 1/4-inch slices and up to 8 hours for thicker slices.
Allow the dried mushrooms to cool completely before storing them.
Storing and Rehydration
Transfer the cooled dried mushrooms to glass jars and cover tightly with lids. Label the jars with the contents including the type of mushroom and the date of drying. Store the jars away from direct light or heat.
To use dehydrated mushrooms, pour boiling water over them in a heat-proof bowl. Soak them for 20 to 30 minutes. Drain the liquid, but save the richly flavored soaking liquid for soup stocks and sauces. Use the rehydrated mushrooms as you would fresh mushrooms.