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
Fish and chips food chains, resulting in a lower fat content per portion. In their homes or in some restaurants, people in or from the United States may eat a thick type of chip, more similar to the British and Irish variant, sometimes referred to as steak fries. In Britain and Ireland, fish and chip shops traditionally use a simple water and flour batter, adding a little sodium bicarbonate (baking soda) and a little vinegar to create lightness, as they react to create bubbles in the batter. Other recipes may use beer or milk batter, where these liquids are often substitutes for water.