Clabbering

Clabbering is the process of allowing milk to sour and thicken naturally without the addition of a starter culture. This occurs when lactic acid bacteria, naturally present in raw milk, consume lactose and produce lactic acid. As the acidity increases, the milk proteins, primarily casein, begin to denature and coagulate, forming a thick, yogurt-like consistency. The resulting product is known as clabbered milk or simply clabber.

Historically, clabbering was a common method of preserving milk before refrigeration was widely available. The increased acidity inhibits the growth of spoilage microorganisms, extending the milk's shelf life. Clabber can be consumed on its own, often with the addition of sugar or fruit, or used as an ingredient in baking and cooking. It can add a tangy flavor and a tenderizing effect to doughs and batters.

The texture of clabber is typically thicker and more curdled than yogurt, with a distinctly sour taste. The rate at which milk clabbers depends on factors such as the ambient temperature and the initial bacterial count in the milk. Warmer temperatures accelerate the process. While clabbering is most commonly associated with cow's milk, other animal milks can also be clabbered.