nonfat buttermilk

Nonfat buttermilk is a liquid byproduct of butter production, specifically the milk remaining after cream is churned into butter, produced with milk fat removed before or after churning. In modern commercial production, it is typically made by culturing nonfat milk with lactic acid bacteria (primarily Lactobacillus lactis), which ferments lactose into lactic acid and develops the characteristic tangy flavor. The result is a thin, pourable liquid with a slightly acidic taste, white color, and consistency similar to low-fat milk. Traditional buttermilk from actual butter-making is rarely found in commercial distribution, as most buttermilk sold today is cultured nonfat milk with added flavoring and thickening agents in some varieties.

Nonfat buttermilk differs from full-fat buttermilk in that the milk fat has been removed, reducing calories while retaining the protein, lactose, and lactic acid content that define its character. The acidity (typically pH 4.4–4.8) is its defining characteristic and primary culinary function.

Nonfat buttermilk is valued primarily as a leavening agent and tenderizing ingredient in baking and cooking. The lactic acid reacts with baking soda to produce carbon dioxide, creating lift in pancakes, biscuits, cakes, and quick breads. It is also used in marinades for fried chicken and other proteins, where the acid and enzymes tenderize meat and impart subtle tang. In dressings, dips, and sauces, buttermilk serves as a creamy base with reduced fat, providing dairy richness without whole milk or cream. It is essential in Southern and Appalachian baking traditions, and appears in cuisines worldwide where cultured dairy products are used. Buttermilk can be substituted for regular milk in most recipes, though it will add tang; it should be used in appropriate proportions to avoid excessive sourness in dishes not intended for acidity.