Sodium bicarbonate

Sodium bicarbonate (IUPAC name: sodium hydrogen carbonate), commonly known as baking soda, is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cation (Na+) and a bicarbonate anion (HCO3−). Sodium bicarbonate is a white solid that is crystalline, but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate). The natural mineral form is nahcolite. It is a component of the mineral natron and is found dissolved in many mineral springs. Sodium bicarbonate (IUPAC name: sodium hydrogen carbonate), commonly known as baking soda, is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cation (Na+) and a bicarbonate anion (HCO3−). Sodium bicarbonate is a white solid that is crystalline, but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate). The natural mineral form is nahcolite. It is a component of the mineral natron and is found dissolved in many mineral springs. Because it has long been known and is widely used, the salt has many related names such as baking soda, bread soda, cooking soda, and bicarbonate of soda. The term baking soda is more common in the United States, whereas bicarbonate of soda is more common in Australia and Britain. In colloquial usage, the names sodium bicarbonate and bicarbonate of soda are often truncated; forms such as sodium bicarb, bicarb soda, bicarbonate, and bicarb are common. The word saleratus, from Latin sal æratus meaning 'aerated salt', was widely used in the 19th century for both sodium bicarbonate and potassium bicarbonate. It is known as one of the E number food additives E500. The prefix bi in bicarbonate comes from an outdated naming system and is based on the observation that there is twice as much carbonate (CO3) per sodium in sodium bicarbonate (NaHCO3) as there is in sodium carbonate (Na2CO3). The modern chemical formulas of these compounds express their precise chemical compositions (which were unknown when the names sodium carbonate and sodium bicarbonate were coined) and show the same ratio the other way around: there is half as much sodium per carbonate in NaHCO3 as in Na2CO3 (disodium carbonate). In cooking, baking soda is primarily used in baking as a leavening agent. When it reacts with acid, carbon dioxide is released, which causes expansion of the batter and forms the characteristic texture and grain in pancakes, cakes, quick breads, soda bread, and other baked and fried foods. Acidic compounds that induce this reaction include phosphates, cream of tartar, lemon juice, yogurt, buttermilk, cocoa, and vinegar. Baking soda may be used together with sourdough, which is acidic, making a lighter product with a less acidic taste. Heat can also by itself cause sodium bicarbonate to act as a raising agent in baking because of thermal decomposition, releasing carbon dioxide. When used this way on its own, without the presence of an acidic component (whether in the batter or by the use of a baking powder containing acid), only half the available CO2 is released. Additionally, in the absence of acid, thermal decomposition of sodium bicarbonate also produces sodium carbonate, which is strongly alkaline and gives the baked product a bitter, 'soapy' taste and a yellow color. To avoid an over-acidic taste from added acid, nonacid ingredients such as whole milk or Dutch-processed cocoa are often added to baked foods. Carbon dioxide production from exposure to heat starts at temperatures above 80 °C (180 °F).