You can also do this in the oven. Step one is the same, then from there… place the mushrooms on a baking paper lined baking tray, again with space between them. Place in a preheated oven (50 degrees C / 120 F) and bake for 1 hour. Check on them, and if they don’t snap when trying to bend them… keep baking and checking every 30 minutes until they do. Then continue following the rest of the steps above.