sourdough

/ˌsaʊərˈdoʊ/

Other forms: sourdoughs

Sourdough is bread that's made with a fermented mixture of flour and water instead of yeast. If you have some sourdough starter, you can easily bake your own sourdough loaf.

Before it came to mean "fermented dough" in the 19th century, sourdough simply meant "leavened bread." Sourdough tastes a tiny bit sour, thanks to the fermentation that helps the bread rise. The practice of saving a piece of dough from a previous loaf and using it to bake another one became especially popular during the 1898 Klondike Gold Rush in the Yukon territories. It was so common, in fact, that sourdough was a well-known nickname for experienced prospectors.

Definitions of sourdough

1. noun

   a bread made of a fermented mixture of flour and water
2. noun

   a leaven of dough in which fermentation is active; used by pioneers for making bread
   type of:

   leaven, leavening

   a substance used to produce fermentation in dough or a liquid
3. noun

   a settler or prospector (especially in western United States or northwest Canada and Alaska)
   type of:

   prospector

   someone who explores an area for mineral deposits

   colonist, settler

   a person who settles in a new colony or moves into new country