Buttermilk

Buttermilk is a fermented dairy drink with a distinct, tangy flavor. It is made by adding lactic acid bacteria to milk. This process changes the milk into a product used for drinking and cooking. People value it for its unique taste and its helpful chemical properties in the kitchen. It can be a refreshing beverage or a vital ingredient for making food rise.

The science of buttermilk relies on the process of fermentation. During this process, bacteria consume lactose, which is the primary sugar found in milk. As the bacteria eat the lactose, they produce lactic acid as a byproduct. This acid causes the pH level of the milk to decrease. As the milk becomes more acidic, a protein called casein begins to precipitate. This means the protein clumps together, causing the milk to thicken or curdle. This thickening is often called clabbering.

There are two main types of buttermilk: traditional and cultured. Traditional buttermilk originated before modern refrigeration and homogenization. In the past, people left raw milk to stand so the cream could separate. Naturally occurring lactic acid bacteria would ferment the milk during this time. This lowered the pH, which helped the fat from the cream coalesce more easily during churning. This traditional version is usually thinner than modern versions. Cultured buttermilk is produced more like yogurt. Manufacturers inoculate pasteurized, homogenized milk with specific cultures. These include Lactococcus lactis, Lactobacillus bulgaricus, or Streptococcus lactis. They may also add Leuconostoc citrovorum to create a buttery quality.

History shows how buttermilk has moved from farm life to grocery stores. In the United States, cultured buttermilk was first sold commercially in the 1920s. It was initially popular among immigrant groups. Sales grew significantly over the following decades. In 1960, buttermilk reached its peak in annual sales. However, consumption has declined since that time. By 2012, annual sales were less than half of the 1960 peak. Today, the food industry still uses condensed and dried buttermilk for many products.

Different cultures around the world cherish buttermilk in unique ways. In Arab culture, buttermilk is often sold ice cold. It is frequently consumed during the holy month of Ramadan. In the Indian subcontinent, people may serve it alongside roasted maize. Traditional buttermilk remains a common household item in South Asia, the Middle East, and parts of Europe.

Buttermilk is highly useful in the culinary arts due to its acidity. In recipes like soda bread, the acid reacts with a leavening agent called sodium bicarbonate. This chemical reaction produces carbon dioxide gas. The gas creates bubbles that help the bread rise. It is also used as a marinade for meats like chicken and pork. In the food industry, liquid buttermilk is used to prepare cheese and baked goods. Buttermilk solids are even used in the manufacturing of ice cream and pancake mixes.

Nutrition and variety are also important aspects of this dairy product. Traditional buttermilk contains very little fat, often less than 0.5 percent. Modern whole buttermilk is composed of 88% water, 3% protein, 3% fat, and 5% carbohydrates. A 100 ml serving provides 62 calories of food energy. It is also a moderate source of vitamins, specifically vitamin B12 and riboflavin. If a cook lacks buttermilk, they can make an acidified substitute. This is done by adding distilled white vinegar or lemon juice to milk. One must let it stand for about 10 minutes until it curdles. This allows the cook to achieve the necessary acidity for their recipe.