Buttermilk is primarily due to lactic acid produced by lactic acid bacteria while fermenting lactose, the primary sugar in milk. As the bacteria produce lactic acid, the pH of the milk decreases and casein, the primary milk protein, precipitates, causing the curdling or clabbering of milk. This process makes buttermilk thicker than plain milk. While both traditional and cultured buttermilk contain lactic acid, traditional buttermilk tends to be less viscous, whereas cultured buttermilk is more viscous. Buttermilk can be drunk straight, and it can also be used in cooking. Soda bread is a bread in which the acid in buttermilk reacts
Sodium bicarbonate salt has many related names such as baking soda, bread soda, cooking soda, and bicarbonate of soda. 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 The prefix "bi" in "bicarbonate" comes from an outdated naming system and is based on the observation that twice as much