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
Cockle bread in which the bread is mentioned: Writing in "Observations on the Popular Antiquities of Great Britain" in 1854, John Brand describes the nursery rhyme as "modern", but adds that its connection to the earlier "moulding" of cockle bread "is by no means generally understood". Cockle bread Cockle bread was an inferior type of British corn or wheat bread mixed with "cockle weed". In the 17th century a practice known as "moulding" cockle-bread had a sexual connotation. Cockle bread is also mentioned in a 19th-century nursery rhyme. The play "The Old Wives' Tale" by George Peele, first published in 1595, has