Q: What are grits? A: Grits are corn!
What are Grits?
Grits are ground up corn (Zea Mays). In grits-eating country they are never referred to in the singular "grit." They are ground from dry field corn, not the sweet corn you eat on the cob during summertime. Field corn stays in the field until the kernels are dry enough to store without getting moldy (under 15.5% moisture content). Although field corn goes through the "milk stage" that sweet corn is harvested at, it's not sweet--it's starchy. Nixtamalized corn is also field corn.
I've been a miller for about twelve years now, so I feel confident I can explain to you in detail the complexities of stone ground grits in a simple but informative way.
Grits are usually associated with the American South, But the food arguably has been a staple over much of the United States in the recent past.
We mill (or grind) stone ground grits. "Stone ground" refers to the mill the corn is ground with. That means the corn was ground on a stone burr mill. There are all kinds of mills. I can think of four different kinds of mills: stone burr, hammer, roller, and flail. Stone=ground products are ground on a stone burr mill. A stone burr mill isn't required to milll grits, but they won't be stone-ground.
No conversation about grits is complete without a brief discussion about corn. Corn is a crop of the Indigenous People of North, Central, and South America. It was first grown in what is today Mexico, in the Oxaca Valley.
Corn is grow all aver the world today in the regions it can be cultivated.
Many Native American cultures were oriented around corn as a staple crop, and they often planted it in a polyculture with squash and beans (the three sisters). The settled monument constructing civilizations of pre-colonial Mexico and The Ohioan people of America most certainly relied on corn as their primary staple grain.
Gerard Paul at manyeats.com wrote a thorough but concise article about corn that covers the topic quite well. Please give it a read here.
This leads us to another word associated with grits: hominy. Hominy is nixtamalized corn. There is reason to believe that Native Americans generally ate nixtamalized corn, which makes corn nutritious (and delicious).
Hominy Grits are grits that contain nixtamalized corn, at least in my opinion.
No nixtamal, no hominy, no hominy grits.
Not all settlers knew that corn wasn't as nutritious without being nixtamalized, and once mills started de-germing their products, pellagra started killing them. This was a problem that was widespread in the American South from the 1860's into the 1900's.
"Stone burr" simply means that the grinding part of the mill is made from stone, i.e., rocks (although some manufacturers use synthetic stones in their mills). "Burr" refers to the carvings on the grinding side of the millstones, A flat stone isn't as good at grinding as a stone that has been shaped with a pattern to assist in grinding grain (referred to as "grist" by millers). This pattern is referred to as "lands" and "furrows." Lands are the high spots, furrows are the low spots. theses shapes interact to cut the grain into uniform sizes.
Millstones may be arranged in a horizontal or vertical fashion. One of the stones called the "runner stone" spins. One stone is stationary, the "bedstone" or "set stone."
Modern stone burr mills are generally powered by electricity, but old-fashioned water-turned mills still count, as do the even more primitive horse-powered mills, or even windmills. For that matter, human turned querns count also. As long as the grinding part of the mill is comprised of stone, the product being milled is stone ground.
To summarize: stone ground grits are corn that has been ground on a stone burr mill.