In a kitchen, small mills are tools used for grinding, crushing, powdering or pulverizing.
Historically much more milling of food stuffs would have happened in the home, but the need for this has lessened as many ingredients can now be purchased already ground to save the cook time and labour.
In broader culinary terms, a mill can be an entire building: for instance, one outfitted with machinery to grind grain into flour. These mills could be operated by water or wind, or powered by animals or humans. Other food related industrial mills include cider mills, oil mills, starch mills and sugar mills.
How mills work
Mills are used with solid materials. The materials can be dry, such as grains or seeds, or they can be moist materials such as tomatoes or other fresh produce.
The force of the pressure in milling breaks up the structure of the solid material, reducing it to much smaller pieces. The volume of the material may change, but the weight of it (unless sieving or straining happens at the same time or after, as is sometimes indeed the case) would stay roughly the same. When sieving or straining is built into a milling tool, it can be difficult to know whether to class such a hybrid device as a mill or a sieve. In these instances, we have let common parlance dictate the classification (e.g. “food mills” despite their straining screens have been classed as mills on the basis of their name alone.)
“To mill” as a verb is to grind or crush solid materials in a mill.
The English word comes ultimately from molinum or molinus (“mill”) in Late Latin, which came from the Latin verb “molo / molere” (to grind, to mill.)
The French word “le moulin” and the German word “die Mühle” share the same origins.
Types of mills
There many different types of mills for home use. They will be either manually operated (via a crank, for example) or electrically operated.