Unleavened refers to a type of bread made without the benefit of leavening agents, known as raising agents. The most popular of these agents is yeast, but other agents include ginger beer, kefir, and sourdough starter.

In Jewish tradition, the term unleavened applies directly to the story of Exodus. The Jews had to leave Egypt so quickly that the bread could not rise. It is also an edict that on Passover we eat unleavened bread. In a Forward article, Professor David Kraemer posits that bread is a product of both biological culture (yeast and sourdough starter) but also the culture of humankind. He goes on to further explain that bread may have originated with the Egyptians, and that in some sense, “unleavened” meant not only to not use the leavening agent, but also so “that Egyptian culture can be left behind.”