First, Clean the Morels
Morels require a bit more cleaning than most mushrooms. A simple swipe with a damp towel won't get the grit out the sponge-like sides of morel mushrooms. Start with a soak in cold water, swish the morels around, and lift the morels out of the water (leaving any grit behind). Drain well and pat morels dry with paper towels or clean kitchen towels. (For more details, check out How to Clean Morels.)
How to Air-Dry Morels
Thread a large darning needle or yarn needle with cotton quilting thread, coat button thread, or old-fashioned un-waxed and un-flavored dental floss. String cleaned morels lengthwise, knotting the thread/floss at each end of each morel mushroom to keep them in place and leaving at least 1/2 inch between each morel so plenty of air can circulate around each mushroom. Hang the strings of morels in a cool, dry place until they are completely dry and brittle, at least 2 days and up to a week.
How to Oven-Dry Morels
You can dry morels in your oven if you can set it to 140°F or less (you don't want to actually cook the morels).
Set cooling racks on baking sheets and arrange the cleaned morels on the cooling racks. Or, remove racks from the oven and use quilting thread, coat button thread, or un-waxed dental floss to tie morels by the stem to the oven racks so the morels are hanging down from the racks. Set the racks back in the oven.
Whether laying the morels on cooling racks or hanging them from the oven racks, heat the oven to 130°F to 140°F and let morels sit until they are completely dry and brittle, about 8 hours.
How to Dry Morels In a Food Dehydrator
Morels dry nicely in dehydrators. Lay them in a single layer on the racks. Set dehydrator to 110°F and dry for about 10 hours.
How to Store Dried Morels
Fully dried morels can be stored in air-tight containers at room temperature for up to 6 months. For longer storage keep them in the freezer.
How to Rehydrate Morels
Dried morels are easy to rehydrate. Simply put the amount you want to use in a bowl and cover with water. Let sit until morels are soft and pliable, about 20 minutes. Resevre the soaking liquid to use in the dish you're cooking, if you like. For risotto and pasta sauces, you may want to soak the morels in boiling water – this will bring out more of the earthy morel flavor into the liquid, which you can then use in the risotto or sauce.