What is Buttermilk?
Buttermilk is a dairy ingredient used and valued for its flavor, nutrition and emulsifying properties in food products. There are several types of available for the baker, including:
- Cultured buttermilk: the thick, tangy, creamy liquid seen on grocery store shelves. It is low fat or nonfat milk inoculated with lactic acid bacteria and can contain thickeners, emulsifiers and colors.
- Sweet cream buttermilk: the liquid leftover from churning cream into butter. The taste is similar to skim milk and approximately 40% of this kind finds use in the baking industry.1
- Buttermilk powder: It is dry, condensed sweet cream variety with less than 30% protein and is convenient to use because of its shelf stability and concentration.
Prior to industrialization, multiple milkings were needed before there was enough cream to churn into butter. Time and temperature allowed the naturally present bacteria in the cream to flourish and culture, resulting in a churned cultured butter and liquid cultured buttermilk.
With industrialization and introduction of refrigeration and pasteurization, processing improvements allowed for different types of this dairy product.
Buttermilk is an important functional dairy product and can improve the nutrition, taste, appearance and texture of baked goods.
Sweet cream buttermilks are excellent emulsifiers due to their phospholipid level which is nine times higher than that of skim milk because of the way it’s processed. Phospholipids are excellent emulsifiers, but are associated with the health benefits of lowering cholesterol and blood pressure.2
Cultured buttermilk, like other fermented dairy products, has a pleasant piquant flavor that results from the added lactic acid bacteria. The bacteria convert some of the lactose in the milk to lactic acid. This acid creates the tangy taste and reacts with the sodium bicarbonate (baking soda) in recipes to produce carbon dioxide and leaven.
Composition and Properties
In general, the composition of sweet and cultured buttermilk is similar to skim milk. It can have more fat because there is not a centrifugal process to remove fat like there is in skim milk production.1
The proteins in sweet cream buttermilk consist of approximately 80% typical milk proteins (casein and whey), while the remainder is the milk fat globule membrane that contain phospholipids.1 Proteins in milk products are nutritious and contain the essential amino acids that the human body needs.
Lactose, the sugar in milk products, has little sweetening power and is not fermented by yeast. Lactose,...