Chicken soup is a soup made from chicken, simmered in water, usually with various other ingredients. The classic chicken soup consists of a clear chicken broth, often with pieces of chicken or vegetables; common additions are pasta, noodles, dumplings, or grains such as rice and barley. Chicken soup has acquired the reputation of a folk remedy for colds and influenza, and in many countries is considered a comfort food. History Humans were already boiling food by the time that chicken was domesticated in the neolithic period, so it is likely that chickens were being boiled for soup. Modern American chicken soup, which typically includes root vegetables such as carrot, onion, leeks and celery, was a staple across Northern Europe and was brought to the United States by immigrants. Preparation Variations on the flavor are gained by adding root vegetables such as parsnip, potato, sweet potato and celery root; herbs such as bay leaves, parsley and dill; other vegetables such as zucchini, whole garlic cloves, lettuce, or tomatoes; and black pepper. The soup should be brought slowly to a boil and then simmered in a covered pot on a very low flame for one to three hours, adding water if necessary. Saffron or turmeric are sometimes added as a yellow colorant. Nutritional value Chicken soup can be a relatively low fat food: fat can be removed by chilling the soup after cooking and skimming the layer of congealed fat from the top. A study determined that "prolonged cooking of a bone in soup increases the calcium content of the soup when cooked at an acidic, but not at a neutral pH". Terminology Strictly speaking, chicken soup, unless qualified, implies that the soup is served as a thin broth, with pieces of meat, and possibly vegetables, and either noodles, rice, barley, or dumplings. Cream of chicken soup is a thick, creamy, soup made with chicken stock and pieces, combined with milk (or cream) and flour, which might contain vegetable pieces, depending on the recipe. Several terms are used when referring to chicken soups: Chicken broth is the liquid part of chicken soup. Broth can be served as is, or used as stock, or served as soup with noodles. Broth can be milder than stock, does not need to be boiled as long, and can be made with meatier chicken parts. Chicken bouillon or bouillon de poulet is the French term for chicken