The English chocolate manufacturer J.S. Fry & Sons made two more important steps toward the mass distribution of chocolate. While other manufacturers had experimented with mechanical grinders, Fry applied a Watts steam engine to the task, providing the model for the mechanized manufacture of chocolate. In 1847, the Fry firm developed another innovation, blending cocoa powder and sugar with melted cocoa butter instead of with water. The resulting paste could be poured into a mold and solidified. The firm was soon selling chocolate bars, which were the first true eating chocolate.
The Swiss made the next strides in Europe towards mass marketing chocolates. In 1867, the chemist Henri Nestlé developed a process to make sweetened condensed milk. In 1879, chocolate manufacturer Daniel Peter conceived the idea of adding the condensed milk to his chocolate, creating milk chocolate. The two men partnered and sold their milk chocolate bars under the name Peter's, a brand that Nestlé S.A. still uses today.
Another Swiss confectioner, Rudolphe Lindt, further improved the processing of chocolate in 1879 through his discovery of conching, although his discovery has most affected the production of fine chocolates. Conching is a trade name for stirring warm chocolate; Lindt discovered that the longer a chocolate is stirred, the smoother and more flavorful it will be.
Milton Hershey (1857–1945), a Pennsylvania Mennonite, deserves credit for the developments in chocolate processing that would allow it to be sold at low prices, in mass quantities. European manufacturers, especially those in Belgium and France, generally remained more concerned with the taste of chocolate than the economies of chocolate production.
Among the more recent innovations is organic chocolate, introduced in response to consumer demand.