Mushrooms

The mushrooms used most often in China, and collectively called gu, are native black mushrooms. Almost never sold fresh in Chinese markets, they come dried in boxes and cellophane packs. They vary from black to dark gray to speckled gray and black, and their caps range from about ¾ inch to 3 inches in diameter. These mushrooms must always be soaked in hot water before use—usually for 20 to 30 minutes, depending on the recipe—and their stems removed and discarded. The dried mushrooms will keep indefinitely in a tightly sealed container at room temperature or, if in a humid damp climate, in the refrigerator. Shiitake mushrooms, known as dong gu, have been eaten throughout China since the T’ang Dynasty. Other dried mushrooms include flower mushrooms, with deep, wide ridges in their caps. Although essentially the same species as black mushrooms, flower mushrooms are thicker, meatier, and more expensive and are so highly regarded that they are often given as gifts. Also popular are small straw mushrooms, which are native to southern China and Hunan; have an elongated, domed cap; and are most often sold canned. Once opened, straw mushrooms will keep in a closed container in the refrigerator for about 1 week. Finally, the so-called chicken leg mushrooms are bulbous and meaty and have almost no cap. They are raised in Canada with spores from China and are usually sold fresh. They lend themselves to cooking with other foods and are long-lived. Wrapped in paper towels and placed in a plastic bag, they will keep in the refrigerator for 10 days to 2 weeks.