The secret to clear soups that sparkle and cream soups that are smooth but not muddy is clarifying the stock.
1. To clarify stock, first strain. Strain stock by ladling it through a colander or sieve lined with 1 or 2 layers of 100-percent-cotton cheesecloth; discard bones, vegetables, and seasonings.
2. Separate an egg (discard the yolk or save for another use). In a small bowl, combine the egg white and 1/4 cup cold water.
3. Stir the mixture into the hot, strained stock. Bring to boiling. Remove from heat and let stand for 5 minutes. (As the egg white cooks, it will coagulate and trap fine particles from the stock.)
4. Place a large sieve or colander lined with several layers of damp 100-percent-cotton cheesecloth over a large bowl. Pour the stock through the cloth to strain out the particles and egg white.