Buttermilk is the liquid left over after producing butter from full-cream milk by the churning process. It has a slightly sour taste. It is quite popular as a refreshment in India. Many breads are made with buttermilk, and it is also used in creamy soups and sauces. Carbohydrates are molecules that contain oxygen, hydrogen, and carbon atoms. ... In chemistry, especially biochemistry, a fatty acid is a carboxylic acid often with a long unbranched aliphatic tail (chain), which either saturated or unsaturated. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... It has been suggested that this article or section be merged with Daily values. ... Butter is commonly sold in sticks (pictured) or small blocks, and frequently served with the use of a butter knife. ... Cream is a dairy product that is composed of the higher-fat layer skimmed from the top of raw milk before homogenization. ... A glass of cows milk Milk is the nutrient fluid produced by the mammary glands of female mammals (including monotremes). ... A young woman churning whole milk into butter Churning is the process of shaking up whole milk (or cream) to make butter, and various forms of butter churn have been used for the purpose. ... Human taste sensory organs, called taste buds or gustatory calyculi, and concentrated on the upper surface of the tongue, appear to be receptive to relatively few chemical species as tastes. ... Taste is one of the most common and fundamental of the senses of animals. ...

Most of the modern, commercially-available, "buttermilk" in supermarkets is not genuine buttermilk but rather cultured buttermilk, that is milk to which souring agents (Streptococci bacteria) have been added to simulate the traditional product. The sour taste, or tartness of "cultured buttermilk" is a result of a fermentation process in which the Lactococcus bacteria turn lactose into lactic acid. As the pH drops in this reaction the milk becomes tart. At this point, casein, a milk protein, precipitates as it is no longer soluble under acidic conditions, causing what is called clabbering or curdling. The acidity of buttermilk inhibits bacterial growth, and this gives it a long refrigeration life. This process can be repeated when making sour cream with slight alterations. Exterior of typical European supermarket (a Tesco Extra) Exterior of typical North American supermarket (a Safeway) A typical supermarket in Hong Kong. ... Species Lactococcus garvieae Lactococcus lactis Lactococcus piscium Lactococcus plantarum Lactococcus raffinolactis Lactococcus is the genus of bacteria formerly known as Streptococcus Group N and related species. ... Lactose is a disaccharide that consists of β-D-galactose and β-D-glucose molecules bonded through a β1-4 glycosidic linkage. ... Lactic acid, also known as milk acid or 2-hydroxypropanoic acid, is a chemical compound that plays a role in several biochemical processes. ... pH is a measure of the acidity of a solution in terms of activity of hydrogen ions (H+). For dilute solutions, however, it is convenient to substitute the activity of the hydrogen ions with the molarity (mol/L) of the hydrogen ions (however, this is not necessarily accurate at higher... Casein is the predominant phosphoprotein found in fresh milk and also in cheese. ... Sour cream is a dairy product rich in fats obtained by fermenting a regular cream by certain kinds of Lactobacillus bacteria. ...

Note that it may be difficult to find buttermilk that is not low-fat in some areas, but it is possible to augment it with cream that has risen to the top of some varieties of store-bought whipping cream. Still, many people enjoy cultured buttermilk as part of a health-conscious diet, particularly in Germany.

In baking, regular milk can be substituted for buttermilk by adding 1 tablespoon of lemon juice or vinegar per cup of regular milk. Allow the soured milk to stand for ten minutes before adding to recipes.[1] This method can be used with soy milk or rice milk for vegan/vegetarian consumption.