Since mushroom powder contains a mixture of edible mushrooms, the exact ingredients and taste vary based on the types of mushrooms used. This dry powder has a long shelf life and often develops additional flavor after a longer period of time. Using mushroom powder is a great way to add a umami flavor, which is often described as a meaty, savory flavor.
“Mushroom powder is a powder that contains only dehydrated pulverized or ground edible mushrooms. It is used as a seasoning for many types of sauces and soups.*”
You might also try sprinkling a little on top of salads or mixing into vegetarian burgers to add extra flavor.
“Whole mushrooms and mushroom pieces — as long as they aren’t spoiled — are used to make mushroom powder. The mushrooms are first chopped and then dehydrated until they are brittle. Finally, the pieces are pulverized using a mortar and pestle, or ground mechanically.*”
“Packed in an airtight container, mushroom powder can be stored for several years. Unlike dried mushrooms, the powder doesn’t have to be soaked or cooked before using in order to develop its flavor.*”
Note (italics): * = Translation from a German Wikipedia entry