For centuries, the only way to make bread rise light and airy was with yeast, eggs or sourdough. Then around the mid-1800s in America, another way to make bread rise began to appear. Chemical leavening agents arrived and the quick bread made its appearance.
I’m sure you have had banana bread? Well, that’s considered a quick bread since it is leavened with baking soda or baking powder. An early form of baking soda was introduced first and was commonly called “Saleratus”. The famous Irish soda bread is a great example of this type of bread.
These chemical leavenings are made of minerals and cause the bread to rise very quickly as it is cooked. There is no need to wait beforehand for the dough to rise. The leavenings worked by creating the air in the bread by means of reactions between the chemicals, typically an acid and a base. This put the lightness in the bread that usually comes from long rising and kneading times.
Quick breads are often more cakey and soft in nature then your typical loaf of bread. Often they have more of a batter consistency then a heavy dough. If you are fairly new to baking, a quick bread may be your best friend!