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 washing with about 6 ounces (170 g) of baking soda in 2 gallons (7.5 l) of water will help to wash it out. Sodium bicarbonate is an amphoteric compound. Aqueous solutions are very mildly alkaline due to the formation of carbonic acid and hydroxide ion: Sodium bicarbonate can be used as a wash to remove any acidic impurities from a "crude" liquid, producing a purer sample. Reaction of sodium bicarbonate and an acid produces a salt and carbonic acid, which readily decomposes to carbon dioxide and water: Sodium bicarbonate reacts with acetic acid (found in vinegar), producing sodium acetate, water,