Chocolate-Making Conch

The chocolate-making conche was named for the resemblance of initial designs to the shell of the conch, a sea-dwelling invertebrate. Invented in 1879 by Rudolph Lindt, the conche is outfitted with large stone rollers that are used to mix and aerate the liquid chocolate. An ad for the "Longitudinal Refining Machine" offered by J.M. Lehmann in an 1899 catalog describes the function of the unit: "In working Chocolate by this machine the highly prized melting character of the chocolate is obtained and besides the taste is considerably improved...No other machine will obtain similar favorable results...[a]s Chocolate handled by this machine becomes very fluid, obviating an excessive addition of Cocoa Butter. . ."

The process of conching is one of the last stages in the production of milk chocolate. It develops the chocolate flavor, darkens the chocolate's color, stabilizes the viscous properties of the chocolate mass by covering all aspects with cocoa butter, and generally lowers the moisture content of the mass. Manufacturing processes vary; some producers add milk, sugar, and flavorings to the chocolate mass or liquor (a semi-liquid ground cocoa bean mixture), before the mixture is refined and conched. Others contend that the heat involved in conching destroys volatile flavor compounds, so flavors are added later. Conching can last from one to four days, and once it is finished, the mixture is melted, deposited into bar molds, and allowed to cool.

The conche was part of a donation by the Hershey Foods Corporation of three machines representing major steps in the chocolate making process: the grinding of "nibs" (the roasted core of the cocoa bean) in the chocolate liquor mill is one of the first steps, the conche performs important mixing and heating functions in the middle of the process, and the depositor ejects milk chocolate that hardens into the final candy bar form. This conche was manufactured in approximately 1920, and was in use at the Hershey chocolate Company.

Milton Snavely Hershey was a candymaker long before he became a significant figure in the American chocolate industry. After failed business ventures in Philadelphia, Denver, and New York, Hershey was finally able to establish a successful trade in Lancaster, Pennsylvania, making caramel candies. He traveled to the World's Columbian Exposition (1893), and visited many of the agricultural and food-related exhibitions there. The J.M. Lehmann Company had a fully functional chocolate bar production line on display in the Machinery Building, and before the close of the Exposition on October 30, 1893, Hershey had arranged to buy the machines that had been in the display. By New Year's Day 1894, Hershey was making cocoa products. He began offering solid chocolate candies in 1896, and, in 1900, the first Hershey's Milk Chocolate bars were offered for sale in Lancaster, Pennsylvania.

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