Analysis of information sources in references of the Wikipedia article "Wet grinder" in English language version.
Melangers typically have a smaller capacity than other industrial mills, so most large makers don't use them; Hershey did, but abandoned them in the 1950s for larger-capacity ball mills. This was about the same time that the electric motor reached India, where melangers were co-opted for making dosas (fermented rice-and-bean creps) because they produce less heat than other mills and preserve the living enzymes in dosa batter.
