Craig Claiborne, in "Craig Claiborne's Southern Cooking" calls salt-rising bread "one of the greatest inventions", and "peculiarly Southern". Popular in the 1800s before yeast was readily available, it relies on a fermented mixture of liquid (often potato water), cornmeal, flour, sugar, and salt as the leavening agent. Other early "risen" breads, after the development of commercial yeast, used a slightly fermented mixture of potatoes and yeast. Potatoes are still a popular addition to breads, which might be attributed to the common fermentation processes used in the past.
In "Joy Of Cooking," the authors offer two starters for salt-rising bread; one made with cornmeal (stone-ground) and the other made with potatoes. They caution not to try the bread in damp, cold weather unless the house is adequately heated, and to protect the batter well from drafts. Even under the best circumstances, results may be erratic, and they offer a few tips. Their bread was successful when in a heavy bowl, covered, then set in a water heated by an electric fry pan or warming tray. You may think up even better methods, but be forewarned the bread is not easy to make and has an unpleasant "cheesy" odor. Craig Claiborne states "...it is not to everyone's liking but it makes excellent sandwiches and toast".
Mary Randolph gives instructions for making Patent Yeast in her cookbook, "The Virginia Housewife" (1824):
Put half a pound of fresh hops into a gallon of water and boil it away to two quarts, then strain it and make it a thin batter with flour; add half a pint of good yeast, and when well fermented, pour it in a bowl and work in as much corn meal as will make it the consistency of biscuit dough; set it to rise, and when quite light, make it into little cakes, which must be dried in the shade, turning them very frequently; keep then securely from damp and dust. Persons who live in towns, and can procure brewer's yeast, will save trouble by using it; take one quart of it, add a quart of water, and proceed as before directed.
In "The Foxfire Book Of Appalachian Cookery", Mary Pitts describes a similar procedure using commercial yeast: "Peel and boil 3 medium Irish potatoes with a handful of peach leaves or hops. Remove the potatoes and mash; strain water in which they were boiled back into potatoes. There should be approximately 3 cups of potatoes and water. Let become tepid. Dissolve two yeast cakes (packages) in one-third cup of water and add to mixture. Add one teaspoon sugar, one-quarter teaspoon salt, and set in warm place to rise overnight. Next morning stir into the yeast sufficient cornmeal to make a very stiff mixture. Let rise again from one and a half to two hours. Now add more cornmeal to make a stiff dough, roll out until one-third inch thick, cut into squares about two inches large, dry in shade, turning until dry and hard. Do not allow to sour, but turn daily until firm. Compressed yeast may be used as a starter. In recipe use one yeast cake for one quart of flour. Two cakes or more may be used if a shorter cooking time is desired."