Updated: Feb 4
While fresh shrooms and truffles can be wrapped in a paper bag or kitchen towel and stored in the refrigerator for up to a month without molding, this doesn't work for long-term storage options or enables you to make accurate and consistent dosing decisions. Drying mushrooms helps prevent the growth of bacteria from the moisture present in the mushrooms.
There are a few ways to dry mushrooms, one of these should work for you.
1. Leaving shrooms out on a towel to dry
Lay the shrooms evenly out on a towel to dry or to decrease the dry time you can also use a fan, set to low, pointing on the shrooms.
2. Using a food dehydrator set to low
This is the best option for drying out shrooms without losing potency like you would with drying in the oven. For $40 or less at a thrift or flea market, you can decrease your dry time from a couple of weeks to overnight. This is also the best choice for those who are in humid climates.
3. The old school tried and true method
Wrap the mushrooms in a dark cloth and leave them in the sun or in front of a fan for a few hours until the shrooms become wrinkly. With the shrooms in this state, they can be stored for a few weeks. For longer storage take the wrinkled and rubbery shrooms and create an epsom salt desiccant. An epsom salt desiccant is created when you fill the bottom of a pan with an even amount of epsom and bake at 250F/120C and bake for 2 hours. Remove the epsom salt from the oven, smash with a hammer, and place the hot desiccant into separate storage containers with air-tight fitting lids. It is important to do the last steps quickly as the desiccant will begin absorbing the moisture in the air as soon as it is removed from the oven. Once the storage containers have the bottoms layered with the desiccant a paper towel should be layered followed by a mesh screen placed on top. Evenly layer the pre-dried mushrooms on the screen and place with the air-tight fitting lid. Store the containers in a cool, dark, dry place and check on the mushrooms every few days. When the mushrooms are cracker dry they are ready to be transferred to a sandwich baggie or in a jar with an air-tight lid. This method requires much patience as it takes a few weeks to reach full dryness.
Both mushrooms and truffles can be stored in an airtight container with a tight-fitting lid in a cool, dark, dry place for a few years without losing potency in these conditions.