Cloud Ears and Wood Ears
Cloud ear - it's a rather exotic sounding name for a type of fungus. Also known as black fungus, tree ears, and jelly mushroom, this dried black fungus has been featured in Chinese cooking since the sixth century A.D. The Chinese name for name for cloud ear is mo-er, or "little ear" - as the photograph below illustrates, it does vaguely resemble a human ear when fresh.
Like tofu, cloud ear - auricularia polytricha to use its scientific name - has no flavor of its own, but soaks in the flavors that it is cooked with. The delicate, crinkly fungus is also valued for its crunchy texture. You'll often find cloud ear added to hot and sour soup, and it is also featured in stir-fried dishes.
Cloud ears are sold mainly in dried form, in plastic bags. If stored in an airtight container, they should keep for up to a year. Before using, soak the fungus in warm water for at least fifteen minutes. It will puff up to several times its normal size. Then rinse the fungus and trim the stem where it was attached to the wood of the tree (cloud ears grow on trees such as the mango and kapok). Once the cloud ears have been cut up into an appropriate shape and size, add them to a dish near the end of stir-frying, so that they do not lose their crunchy texture.
Although the two are often confused, wood ears are actually a distant relative of the cloud ear fungus. Larger and somewhat tougher, they lack the delicate taste of cloud ears. Storage and preparation of wood ears is virtually identical to cloud ears, except that they can be soaked in cold instead of warm water. They are also used in soups and stir-fries.
Photograph of cloud ear fungus courtesy of David Levy at FungaLuscious, Inc.