broth. Chicken consommé is a more refined chicken broth. It is usually strained to perfect clarity, and reduced to concentrate it. Chicken stew is a more substantial dish with a higher ratio of solids to broth. The broth may also be thickened toward a gravy-like consistency with a roux or by adding flour-based dumplings (matzah balls do not have the same thickening effect). Chicken stock is a liquid in which chicken bones and vegetables have been simmered for the purpose of serving as an ingredient in more complex dishes. Chicken stock is not usually served as is. Stock can be made with less palatable parts of the chicken, such as feet, necks or bones: the higher bone content in these parts contributes more gelatin to the liquid, making it a better base for sauces. Stock can be reboiled and reused as the basis for a new stock. Bouillon cubes or soup base are often used instead of chicken stock prepared from scratch. Alleged medicinal properties Chicken soup has long been touted as a form of folk medicine to treat symptoms of the common cold and related conditions. In 2000, scientists at the University of Nebraska Medical Center in Omaha studied the effect of chicken soup on the inflammatory response in vitro. They found that some components of the chicken soup inhibit neutrophil migration, which may have an anti-inflammatory effect that could hypothetically lead to temporary ease from symptoms of illness. However, since these results have been obtained from purified cells (and directly applied), the diluted soup in vivo effect is debatable. The New York Times reviewed the University of Nebraska study, among others, in 2007 and concluded that "none of the research is conclusive, and it is not known whether the changes measured in the laboratory really have a meaningful effect on people with cold symptoms." It has also been shown that chicken soup contains the amino acid cysteine, which is very similar to acetylcysteine, which is used by doctors for patients with bronchitis and other respiratory infections to help clear them. Chicken soup is also known as "Jewish penicillin", either as ersatz penicillin, or as alternative to penicillin. In different cultures China Many Chinese soups are based on chicken broth. Typical Chinese chicken soup is made from old hens and is seasoned with ginger, scallions, black pepper, soy sauce, rice wine and sesame oil. A more elaborate version can