Henry Ford turned car-factory sawdust into the Kingsford charcoal briquette
Backyard barbecue briquettes owe a debt to the car industry. Ellsworth Zwoyer of Pennsylvania patented the American briquette in 1897, but Henry Ford popularised it by feeding leftover wood and sawdust from automobile production into the process. His Ford Charcoal business went on to become the Kingsford Company, still a familiar name on grilling bags.
Charcoal is what remains when wood is heated hard with too little oxygen to burn, driving off water and volatile compounds and leaving mostly carbon. The traditional way was to stand billets on end in a cone around a central flue, smother the pile in turf or damp clay, and light it from the bottom so the fire crept outward and upward. In Britain a covered clamp smouldered for about five days. Balancing the burn was so delicate that it fell to colliers, professional charcoal burners who often lived alone beside their piles; in Germany's Harz Mountains their conical huts, called Köten, still stand.
Efficiency was poor. Wood typically yielded about a quarter of its weight as charcoal, and the smouldering released plenty of methane. Modern retorts, heated by burning the gases the wood gives off, can reach 35 to 40 percent. Temperature shapes the product: charcoal made around 300 degrees Celsius is soft and catches fire easily, while charcoal made hotter is hard and brittle and will not ignite until roughly 700 degrees.
Its greatest role was in metalworking. Charcoal burns above 1,100 degrees Celsius, and controlling the airflow lets a smith regulate the heat, which is why forges still use it. Artifacts from Proto-Hittite layers at Kaman-Kalehöyük show it was used for making iron and steel by at least 2000 BCE. The appetite of furnaces was enormous: charcoal burning employed hundreds of thousands at its height, stripped forests across Central Europe, and in the 16th century pushed England to pass laws protecting its trees. English coppicing, cutting woods to regrow on a cycle, kept supplies steady, but scarce timber eventually drove industry to coal and, in the 19th century, to coke.
Specialised varieties abound. Japan's white binchōtan rings with a metallic note when struck. Activated charcoal is heated to about 900 degrees in inert gas until riddled with pores that trap chemicals, and exceptionally pure sugar charcoal served Henri Moissan in his early attempts to make synthetic diamonds.
Source: Charcoal
