Manual burr grinders are turned by hand, rotating one grinding surface against the other. Coffee mills usually have a handle, providing leverage for the many turns required to grind enough coffee for a cup. The ground coffee is collected in a container which is part of the mill.
Salt, pepper, and spice mills, essentially the same as coffee mills, usually do not have a handle, the entire top rotating instead. While this is less convenient, only a few turns are required to grind enough. The ground product falls directly onto the food being seasoned; the mill has no container. A few designs have abrasive surfaces which do not rotate; each squeeze of the handles moves one flat plate past another, then the plates are restored to their original position by a spring. Many hard spices are available in containers incorporating a simple cone burr grinder, intended to be discarded when empty.
Most grinders can be adjusted to set the fineness of grind.
Manual mills can be used for grinding other food products than they are intended for, but mills designed for pepper grinding are inappropriate for producing finely-ground flour. Laura Ingalls Wilder's novel The Long Winter describes a family grinding wheat in a coffee mill to make flour during months of hardship.
The first Coffee Grinder was made by Richard Dearmann, an English blacksmith from Birmingham, in 1799. Then this grinder was widely distributed in the US, where Increase Wilson patented the first wall coffee grinder in 1818.[citation needed]
Peugeot of France patented a Pepper Grinder in 1842. The mechanism of case-hardened steel cracked the peppercorns before the actual grinding process. The grooves on the Peugeot mechanism were individually cut into the metal and then case-hardened, making them very durable.[citation needed]
Pepper Mill, Salt Mill, Pepper Grinder, Plastic Kitchen Gadget, Kitchen Gadget
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