In cooking, leaveners are agents that cause a dough, batter or other mixture to rise and expand by creating gas bubbles in it. This affects the texture of the baked good, making it lighter.
Leaveners are generally classed as “natural leaveners” or “chemical leaveners” (not that the chemicals involved aren’t natural ones, anyway.)
For example, yeast is a natural leavener; baking powder is a chemical leavener.
Unleavened baked goods don’t have the rising happening in them, and therefore are denser and heavier.
Types of leaveners
Chemical Leaveners
Chemical leaveners revolutionized how people cooked at home. They made possible not only quick breads such as baking powder biscuits, but whole new ranges of baked goods.
Starters for bread
A bread starter is a very moist piece of dough innoculated with yeast in some manner. It is used as the basis for bread, in which it becomes the leavener.
Yeast
Yeast is a one-cell, plant micro-organism: essentially, a fungus.
The main variety of yeast that we use in the food world is "saccharomyces cerevisiae." This is often referred to as "baker's yeast."
We use yeast to kick off fermentation in bread...