Coke is a residue of coal obtained through a process known as destructive distillation. Special ovens are used to burn off the volatile matter—tar, oils and gases—in the coal, leaving mainly fixed carbon. Coke is used primarily in blast furnaces to make pig iron. It serves both as fuel to heat the iron ore and limestone and, by replacing the oxygen in the ore with carbon, as an ingredient in the steel. For centuries, charcoal was used in ironmaking, but a shortage of wood in Great Britain led ironmaster Abraham Darby to distill the world's first coke in 1711. With more plentiful wood, American ironmakers relied on charcoal until the 1840s, when unprocessed anthracite coal was widely adopted for furnace fuel. Coke made from bituminous coal displaced anthracite as the leading blast furnace fuel in America in 1869.

The first coke made in West Virginia was produced in Monongalia County on the banks of the Cheat River in 1843 for use in the Cheat Mountain iron industry. Coke making did not become an important industry in the state until the late-1880s. Coke production increased dramatically during the next 20 years, hitting an all-time high of 4,217,381 tons in 1910. McDowell, Fayette, Marion, and Preston were the leading coke-producing counties. Coke was made near the mines in beehive ovens—brick and stone enclosures with domed tops shaped like beehives. The ovens were loaded or "charged" with coal and sealed with firebricks to restrict the amount of air. The heat stored in the oven from the previous charge ignited the fresh coal. Coal gases escaped through the crown of the oven as noxious smoke. After 72 hours, the coking was complete, and the coke was quenched with a stream of water. During the 1910s, beehive ovens were displaced by more efficient byproduct ovens, which captured the escaping volatile matter for use in making chemicals. West Virginia had few byproduct plants, so the state's coke industry declined; beehive production dwindled to 836,738 tons in 1921. Beehive coke continued to be produced in the state, however, until 1981, when the ovens at Bretz in Preston County were shut down.