Troy & Sons Distillery is an awesome story that you can read online about a distillery that uses a special type of corn, "Crooked Creek" Corn.
Here is a bit of history of "Crooked Creek" Corn.
"The corn had become virtually extinct everywhere except on the McEntire Farm...believed to be lost from Eastern Tennessee since 1840. Crooked Creek Corn™ is an heirloom open-pollinated white corn that has been grown on the McEntire farm for over one hundred twenty years. Analyzed by researchers at the University of Tennessee, this "lost corn" is an unadulterated, non-genetically modified original American corn, making our moonshine a true American spirit." Source | Troy & Sons Distillery Our Story
Also, check out their video on soil testing. This is the video that originally led me to this site.