Dried shiitake refers to shiitake mushrooms that have been dehydrated. Mushrooms have a high water content and can spoil quickly, but drying them can increase shelf life while preserving their flavor. Shiitake mushrooms, also called Black Forest or Japanese mushrooms, are an Asian variety, and dried shiitake is common in Chinese, Japanese, and Korean cuisine as well as in some Thai dishes. Technically, shiitake mushrooms are edible sporophores, or spore-making fungus, and they form on the bark of trees.
In its fresh form, a shiitake looks a lot like a common, button mushroom in shape but it is flatter on the top and has a much thinner stem. It is also darker in color, mostly tan or light brown and grayish underneath its cap. Grocery and specialty stores sell dried shiitake whole, as caps or top parts only, or as mixed pieces, and often the dried varieties are shrunken or shriveled-looking from having their water pulled out through the dehydration process. Many cooks find the stems inedible, but others note that they are easier to work with when dried and then rehydrated.
Fresh shiitake is very flavorful and adds texture to soups and salads, among other dishes, and dried shiitake retains its mushroom taste. Often the flavor intensifies, taking on a richer or nuttier quality. Using dried shiitake involves rehydrating or reconstituting the mushroom. Water, wine, and soup stocks are some liquids used to add water back into dried mushrooms, and in addition to reviving the mushroom, the liquid takes on much of the flavors and can be used to enhance a recipe.
Some common dishes made with dried shiitake are pastas, soups, and stir-fries. While the stems of fresh shiitake mushrooms can be tough or chewy in texture, a number of recipes call for adding them as flavoring for gravies and sauces and chopping them finely or discarding them afterward. Most methods of cooking, whether fried, sauteed, or broiled, for example, seem to heighten the meatiness of dried shiitake, giving it a heavier and deeper taste similar to that of portobello mushrooms.
According to the American Cancer Society, dried shiitake may be an ingredient for good health as well. Compounds within the mushroom have been shown to reduce cholesterol, fight cancer, and impede tumor growth in some studies, but results are not definitive. Many Chinese and Japanese practitioners have treated patients with dried shiitake extracts for centuries, and these methods have been gaining ground in Europe and the United States in more recent decades. Whether or not the benefits are conclusive, the shiitake will likely continue as one of the most commonly eaten fungi in the world for taste alone.