Barbecue grills and kettles began appearing as American suburbs expanded in the 1950s. They replaced the brick barbecues of an earlier time for a more mobile population. George Stephens designed his first barbecue kettle in 1952. The company he founded produces Flavorizer bars as a protective device to minimize flare-ups in its products.
Once the problem of keeping a fire going in a tin can was solved, the next challenge for every company that produced barbecues was how to control fat as it dissolved in the heat. A well-marbled steak or ground-chuck hamburger sheds as much as 20 percent of its weight in cooking. In an oven, this moisture and fat falls into a broiler pan; over an open fire, the steak can be moved to another area as the fat flares up on red-hot embers. On a three-foot-square grill over charcoal, however, fat falls directly onto the coals, creating a flare-up that can engulf the meat and singe it to a crisp.
When gas grills began to appear in the 1960s, manufacturers protected burners by setting nonflammable materials on a rack over them to catch dropping fat. Fat burned slowly off the materials, but it did so slowly, minimizing or eliminating flares altogether. Lava rocks were the first materials used as fat-catchers. Unfortunately, they soaked up fat as well as held it away from the burners, so they had to be replaced periodically. Ceramic briquettes came next, and they did a better job of spreading out fat without absorbing it. They could be cleaned or turned over to burn off fat after cooking concluded. Ceramic briquettes and tiles still shield gas burners in many designs. Tiles are perforated to allow air to maintain a draft for the fire.
Flame tamers began appearing as an alternative to lava rocks and briquettes that had to be maintained and replaced regularly. The basic concept of the flame tamer is to provide a slanted metal or ceramic assembly that fits into the body of the barbecue over the burners to increase the area that holds grease away from the burners. Some flame tamers are single sheets of metal in a tent shape that sits in the body of the cooker. Others resemble broiler grills, and some look like old-fashioned radiator grills. Others are long, narrow metal tents set across a grate.
Weber entered the gas-grill market in the 1980s with its Genesis series. Set into these gas grills were a half dozen or more right-angled metal pieces, patented as Flavorizer bars, that formed a grid over the gas burners. They were not just flame tamers, according to Weber -- they held the meat drippings long enough to set them to smoking, returning the flavor lost in fat drippings to the meat. The design worked, and all of Weber's current models contain Flavorizer bars. The designs vary, and the materials include enameled steel and stainless steel.