How it began
Rodolphe Lindt, a young chocolatier in Bern, spent years trying to make a chocolate with a better texture and flavor. In 1879 he arrived at the conching process. According to the company's own account, it was allegedly the result of chance: one weekend he either forgot to, or chose not to, turn off a machine, and after three days he came back to a velvety chocolate that was easy to pour into molds. Other versions of the story differ, and it may be apocryphal. He called the result chocolat fondant, melting chocolate.
Before it existed
Molded chocolate of the time often consisted simply of cocoa mass and sugar and was coarse by comparison. Chocolate was consumed mainly as a drink. The machine Lindt worked with was an older water-powered grinding machine developed in the early 1800s by an Italian named Bozelli, itself based on the old Mesoamerican practice of grinding cocoa beans on curved stones. Lindt modified it for his purpose.
How it works
Lindt's original conche had a granite roller moving back and forth in a granite trough, whose ends were shaped to throw the chocolate back over the roller and expose it to air. The long stirring spreads cocoa butter evenly around the solid particles and breaks up clumps. Frictional heat and air drive off moisture and unwanted acids, which mellows the flavor. Extra cocoa butter is added, and the powdery mass becomes a liquid ready for molding. The name comes from the shell-like shape of the early vessels.
How it spread
Lindt built a separate conching building with access limited to authorized staff, and the process remained mostly a trade secret until the end of the century. In the 1890s Cailler launched a similar chocolate, and the machine builder J. M. Lehmann made a long conche from 1899, the year Lindt & Sprüngli began. Conching was a standard process in the chocolate industry by the 1920s.
What lasted
Conching made the mass production of chocolate bars more practical, and bars in time replaced drinks as the main way chocolate was consumed. It also made the addition of extra cocoa butter general practice. Chocolate makers around the world still conch. A modern rotary conche handles 3 to 10 tonnes in under 12 hours, where the original long conche needed more than a day for one tonne.
