The broth is a food liquid obtained by prolonged boiling of lightly salted water and enriched with different vegetables, in which meat, chicken, or fish are immersed. A good broth is prepared following very specific rules; the most important is to put the cold meat in water (this system is called "cold infusion"), so that the liquid, boiling slowly and progressively and penetrating into the meat fibers, dissolves all their soluble parts and enrich it with the best substances acquiring flavor (while the meat remains insipid). These substances, with the increase of heat, coagulate forming a kind of foam that emerges during the first phase of cooking, and which must be removed with a skimmer.
Another important rule is to keep a light boil and the container covered, to avoid excessive water evaporation.
The ingredients to prepare a good broth are: white rib of beef or brisket, a bone with marrow, a piece of muscle or shank (which makes the broth more tangy and gelatinous) plus some vegetables such as carrot, onion, and celery.