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
Buttermilk common drink in many Nepalese homes. It is served to family members and guests, and can be taken with meals or snacks. In many families, it is most popularly served with roasted maize. Buttermilk can be made at home by whisking a cup of non-homogenized cream until it separates into butter and buttermilk. Commercially available cultured buttermilk is milk that has been pasteurized and homogenized (with 1% or 2% fat), and then inoculated with a culture of "Lactococcus lactis" plus "Leuconostoc citrovorum" to simulate the naturally occurring bacteria in the old-fashioned product. Some dairies add colored flecks of butter to