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A snack vending machine
Stop at almost any checkout counter and you'll find dozens of varieties of candy bars. In the United States, where people consume an average of 10 kilograms (22 pounds) of candy each per year, candy bars are associated with popular holidays like Halloween and Valentine's Day. In Scotland, the deep-fried Mars bar, dipped in batter and immersed in a vat of boiling oil, swept the country in the late 1990s.
Some 150 new candy bars hit the shelves every year, but 65 percent of U.S. brands have been around more than six decades. The first composite bar, the Goo Goo Cluster, debuted in 1912, luring buyers with its mix of milk chocolate, caramel, marshmallow, and nuts. The 1920s were the heyday of candy bars, with the emergence of brands like Three Musketeers, Baby Ruth, and Snickers-still the best-selling bar of all time. (More short-lived were the Chicken Dinner and Tummy Full, touted as cheap meal substitutes during the Great Depression.)
Mars and Hershey control 75 percent of the U.S. candy rack. Switzerland's Nestlé is the world's largest chocolate producer, and British candy bars, like the Cadbury Crunchie, maintain a strong following worldwide.
Production
The history of candy bars is a quest for ways to produce a more consistent product at lower cost. In 1958, Mars was able to cut the time spent per bar from 16 hours to 35 minutes. Today, precision machines mix, shape, and package bars at a rate of several hundred a minute.

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Cocoa on Nias Island, Indonesia
The resulting mixture is kneaded between large steel rollers to make a smooth paste, and then "conched," or heated, mixed, ground, and stirred, to develop its flavor. An enrober is used to shower the liquid chocolate on lines of fillings, such as nougat, wafers, and caramel, most derived from water- and chemical-intensive commodities like corn, flour, and sugar. The bars then are wrapped and shipped to stores via truck or airplane. Once the candy is eaten, the wrapper is simply tossed, ending up in landfills or the open environment.
Doing It Better
Concerns about the use of child labor have sparked ambitious efforts to regulate chocolate production. The 2001 Harkin-Engel protocol aims to ensure that half the cocoa originating in West Africa, a leading producer, is free of exploitative child labor by July 2008. In general, the trend is toward "gourmet" products, including items that are handmade, made with local and organic ingredients, and fairly traded. The organic chocolate market is growing by more than 50 percent annually, and Mars, Hershey, and other candy makers are developing "artisan" brands.