"My Quest for a Non-GMO Corn Tortilla"
"...At home, I went online to Bob’s Red Mill’s website, where I found that Bob’s says the corn is organic, but because it’s soaked in lime before being dried and ground, it can’t be labeled as such. Soaking the corn kernels in lime water is called nixtamalization, and it changes the amino acid profile of the corn, making its lysine and tryptophan amino acids more available, resulting in a greater abundance of niacin—the shortage of which causes a terrible disease called pellagra. Nixtamalization was discovered by Mexico’s native populations thousands of years ago. Pellagra can be common in people who obtain most of their food energy from corn, notably people who live in rural Central and South America, where corn is a staple food. If corn is not nixtamalized, it is a poor source of lysine and tryptophan, thus of niacin. If the national organic rules say that nixtamalization disallows corn that’s grown organically from being labeled organic, than the rules are wrong and need to be changed. There’s nothing un-organic about soaking corn kernels in water that contains wood ashes—as the Native Americans did—or in lime water, which is just naturally occurring calcium carbonate—limestone—that is already allowed as a soil and compost ingredient under the national organic rules."
~ Jeff Cox
lime water is calcium hydroxide. While it is usually made by heating calcium carbonate, natural occurrences are rare.
From a 2005 article
"Mr Harvey took his case to court, claiming that the rules allowing synthetics violated a 1990 law passed by Congress, which he says permits only natural products in manufactured "organic" food. ...Manufacturers argue that the synthetics they are using are USDA- approved, innocuous but essential materials such as baking powder, Vitamin C, and lime (calcium hydroxide) - used to process cane sugar.
Sounds like the same ruling that forces 'organic bacon' manufacturers to use celery juice instead of chemically pure sodium nitrate/nitrites.