Broth is a liquid food preparation, typically consisting of either water or an already flavored stock, in which bones, meat, fish, cereal grains, or vegetables have been simmered. Broth is used as a basis for other edible liquids such as soup, gravy, or sauce. It can be eaten alone or with garnish. If other ingredients are used, such as rice, pearl barley or oats, it is then generally called soup.
In Britain, a broth is defined as a soup in which there are solid pieces of meat or fish, along with some vegetables. A broth is usually made with a stock or plain water as its base, with meat or fish added while being brought to a boil, and vegetables added later. Being a thin and watery soup, broth is frequently made more substantial by adding rice, barley or pulses. Broth is distinct from stock, which is a thin liquid made by simmering raw ingredients until all the taste has been retrieved from them, then sieving the resulting liquid.
United States cooking schools often differentiate between broth, usually made from portions of animal meat, and stock often made from vegetable scraps and bones.
Broth has been made for many years using the animal bones which, traditionally, are boiled in a cooking pot for long periods to extract the flavor and nutrients. The bones may or may not have meat still on them.
When it is necessary to clarify a broth (e.g. for a cleaner presentation), egg whites may be added during simmering – the egg whites will coagulate, trapping sediment and turbidity into a readily strainable mass. By not allowing the original preparation to boil you will increase the clarity.
Roasted bones will add a rich flavor to the broth but also a dark color.
In East Asia (particularly Japan), a form of kelp called kombu is often used as the basis for broths (called dashi in Japanese).