Quick bread leavening process, agents (one or more food-grade chemicals—usually a weak acid and a weak base) are added into the dough during mixing. These agents undergo a chemical reaction to produce carbon dioxide, which increases the baked good's volume and produces a porous structure and lighter texture. Yeast breads often take hours to rise, and the resulting baked good's texture can vary greatly based on external factors such as temperature and humidity. By contrast, breads made with chemical leavening agents are relatively uniform, reliable, and quick. Usually, the resulting baked good is softer and lighter than a traditional yeast bread. Chemical
Bread and butter pudding can be used instead. Sometimes raspberry, strawberry, blackberry or mixed fruit jam, marmalade, or other sweet preserves will be spread upon the bread, along with the butter. Other modern variations include scattering fresh grapes between the layers of bread, melting apples into the egg-milk mixture, and using unusual types of breads — such as brioche — to make it. Lemon or orange peel will add a characteristic flavour. The earliest bread and butter puddings were called "whitepot" and used either bone marrow or butter. Whitepots could also be made using rice instead of bread, giving rise to the rice pudding