Consommé is the most sophisticated of all stock-based soups. It is made by reducing veal, beef, chicken or, less frequently, game or fish stock and then clarifying it to produce a limpid, sparkling liquid. Its transparency is deceptive since good consommé has punch—a heady aroma and strong flavor that is neither bland nor salty, thin nor heavy.
The clarification process is simple. Well-flavored, fat-free stock is brought slowly to a boil while egg whites are whisked in. As the egg whites cook, they rise to the top of the stock in a gray froth that coagulates to form a filter. The consommé is left to simmer for about an hour so that the impurities percolate up through the filter leaving the liquid clean and sparkling.