clabber

Clabber is milk that has thickened and developed a tangy flavor through lactic acid fermentation. It occurs when milk is allowed to sour at warm or room temperature, enabling lactic acid bacteria to multiply. Clabbered milk can be made from raw or pasteurized milk and may be started with a small amount of previous clabbered milk, yogurt, or buttermilk to speed fermentation.

Historically common in rural and traditional cuisines, clabber has been used as a beverage and as a souring agent in cooking and baking. It can replace or complement other cultured dairy products like yogurt or buttermilk in recipes for pancakes, cakes, biscuits, dressings, and custards, providing moisture and a distinctive tang.

Preparation and variations are flexible: dairy environments and temperatures influence the rate and character of fermentation, and clabber can range from softly thick to almost spoonable. Some people refrigerate clabbered milk to slow fermentation and preserve it as a sour milk drink or as an ingredient in baked goods. In modern kitchens, clabber is often made by intentionally souring milk with a starter, but it can also form naturally in raw milk left to ferment. Safety hinges on clean handling and storage; discard clabber that develops mold, off odors, or signs of spoilage.