A round wok, also called a round-bottom or classic wok, is the original type of wok. These woks can come in a variety of materials and sizes. Using a round wok has its benefits, but it also has its downsides, which largely result from the design of modern day stoves. A cook may need to use a device known as a "wok ring" in order to adapt his or her round-bottomed wok to the stove-top.
Traditional round woks are made of carbon steel and have a diameter of 14 inches (35.6 cm). A consumer can purchase a wok with a diameter as small as 10 inches (25.4 cm) or as large as 16 inches (40.6 cm). Manufacturers also sell round woks made of cast iron, stainless steel, and aluminum. Each material has its own pros and cons, and a consumer shopping for a wok should research these choices before selecting the right material for his or her culinary needs.
A classic, round wok has a rounded bottom. Its counterpart, the flat bottom wok, has a flat spot on the bottom so the pan can rest upright on a flat surface. Originally, woks were designed to work with a Chinese pit-style stove. The round bottom of the wok rested in a hole in the stove's surface. A fire lit inside that hole and directly beneath the wok surrounded the entire pan with heat.
Round woks make stir-frying easier. A traditional wok spatula has a rounded edge meant to glide along the rounded interior of the wok. This rounded spatula, when matched with the smooth surface of the round wok, simplifies the process of tossing the individual pieces of food inside the pan. Introducing a flat surface makes tossing the food more difficult and may produce food that is less evenly cooked.
The design of the standard stove-top makes a round wok less efficient, however. Electric stoves, especially induction stoves, do not often produce enough heat to climb along the sides of the wok and heat the entire pan. Round woks work better with gas stoves, since the fire beneath the wok generates more heat above the burner than electric heating elements can generate. Cooks can use a round wok with either type of stove if they have the right sort of wok ring, though.
Specially designed wok rings help stabilize the pan and evenly distribute the heat. This circular piece of metal fits onto the stove and provides the round-bottom wok with a place to rest. In general, a wok ring should be approximately 4 inches (around 10 cm) smaller in diameter than the wok itself.
The type of wok ring a cook should use for his or her round wok mostly depends on the type of stove the cook has. An open ring made of wire works best with a gas stove. The air circulation provided with an open ring allows the fire produced by the gas stove to hug the sides of the wok. A closed ring is made of solid metal and contains small holes for ventilation. These rings work best with an electric burner since the additional metal conducts heat better and transfers it directly to the metal of the wok.