A crock pot on the wood stove with birch polypore, chaga, maitake, and shiitake makes a bitter tonic. Published October 9, 2016 at 1936 × 2592 in Medicinal Fungal Finds A crock pot on the wood stove with birch polypore, chaga, maitake, and shiitake makes a bitter tonic. A crock pot on the wood stove with birch polypore, chaga, maitake, and shiitake makes a bitter tonic.