" The miso store entailed much sampling. Although all miso consists of crushed boiled soybeans, salt, and a fermenting agent called koji, the types differ based on whether rice, wheat, or barley is added to the mix. The flavor and color of each style can also change, depending upon the amounts of soybeans, type of koji (made from either beans or grains, inoculated with the mold Aspergillus), and salt that are added, as well as how long the miso ages. Brick-red miso, for example, comes in both sweet and salty varieties and is made with either barley or a mixture of barley and rice. Because it tastes somewhat coarse, it usually seasons hearty dishes, such as brothy seafood stews. Similar in flavor is the chocolate-brown miso. Mainly composed of soybeans, it has a bold earthy tang best enjoyed in robust dishes, such as potatoes simmered with miso.
Shiro miso, or "white miso," is a Kyoto specialty. Smooth, golden, and quite mellow, it is said to have evolved to suit the tastes of the effete aristocracy during the fourteenth and fifteenth centuries. It is used extensively in Kyoto cooking, including tea kaiseki, and often comes seasoned with herbs, citrus, and mustard. Because of its delicate nature, it tends to be used as a sauce, mainly to dress vegetables and grilled foods. A saltier version appears most often in American markets. "

― , Untangling My Chopsticks: A Culinary Sojourn in Kyoto