Wikipedia Abstract
in the form of salt crystals, together with starch to keep it dry. When dissolved in water the acid and alkali react and emit carbon dioxide gas, which expands existing bubbles to leaven the mixture. Most modern baking powders are double acting, that is, they contain two acid salts, one which reacts at room temperature, producing a rise as soon as the dough or batter is prepared, and another which reacts at a higher temperature, causing a further rise during baking. Baking powders that contain only the low-temperature acid salts are called single acting. Many recipes call for a process called creaming, where butter and sugar are beaten together to introduce tiny seed bubbles which the leavening gas will further expand. Common low-temperature acid salts include cream of tartar, calcium phosphate, and citrate. High-temperature acid salts are usually aluminium salts, such as calcium aluminium phosphate. They can be found not only in many baking powders, but also in many non-dairy coffee creamers. Excess aluminium in the diet may be detrimental to human health[http://www.emedicine.com/med/topic113.htm], and so baking powders are available without it for people who are concerned and those sensitive to the taste. While various baking powders were sold in the first half of the 19th century, our modern variants were discovered by Alfred Bird. Eben Norton Horsford, a student of Justus von Liebig, who began his studies on baking powder in 1856, eventually developed a variety he named in honor of Count Rumford. August Oetker, a German pharmacist, made baking powder very popular when he began selling his mixture to housewives. The same recipe he created in 1891 is still sold as Backin in Germany. Oetker started the mass production of baking powder in 1898 and patented his technique in 1903. In 2006 the development of Rumford Baking Powder was designated an ACS National Historical Chemical Landmark in recognition of its significance for making baking easier, quicker, and more reliable."[http://acswebcontent.acs.org/landmarks/bakingpowder/bakingpowder.html]"
via dbpedia.org