Salt-rising (or salt-risen) bread is a dense white bread that was widely made by early settlers in the Appalachian Mountains in a process that involves no yeast. Instead, the leavening agents are wild organisms ubiquitous in nature. Salt in the name is a misnomer, since the salt levels are relatively low, around 20 mg per slice. It is thought that the salt used in the starter is used to suppress yeast growth and provide an environment more conducive for the microbes to grow, enhancing the distinct flavors which predominate over the more typical yeast flavors. Another assumption regarding the name is that chunks of rock salt were heated and used to provide a warm, stable temperature in which to incubate a "starter" overnight. Salt-rising bread is made from wheat flour, with a starter consisting of a liquid (water or milk), either corn, potatoes, or wheat, and some other minor ingredients. The starter distinguishes itself from a sourdough starter by working best with an incubation period of 6–16 hours at temperatures ranging from 38–45 °C (100–113 °F); a sourdough starter will usually work best at or below room temperature. The resulting bread is of a dense crumb and favorable cheese-like flavor.
Salt-rising bread has a very recognizable and pungent odor which some people find very pleasant and others consider very unpleasant. Regardless of preference, the odor tends to diminish when the bread is toasted. One typical way of serving this bread is as toast.
The exact origin of this bread is unknown, but evidence suggests that it was the pioneer women in early American states who discovered how to make bread without yeast. Commercial yeast was not available until the 1860s. Currently, the tradition of making salt-rising bread is kept alive by relatively few individuals and bakeries that tend to be clustered in the central to eastern United States. It is particularly popular in Kentucky, West Virginia, Western New York, and Western Pennsylvania.