How to Make Shellfish Stock

Ingredients

• 1  bay leaf 
• 1  carrots roughly sliced chopped
• 1  celery stalk roughly sliced chopped
• 0.5 cup cooking wine dry white
• 1 sprigs several parsley 
• 2 teaspoons salt 
• 4 cups shellfish shells 
• 2 sprigs thyme leaves 
• 2 Tbsp tomato paste 
• 10  peppercorns whole
• 1 large onion yellow sliced chopped

Equipment

• bowl
• pot
• sieve
• roasting pan
• stove
• ziploc bags
• rolling pin
• slotted spoon
• cheesecloth
• kitchen twine
• chefs knife

Directions

1. Break thick shells (lobster and crab) into smaller pieces by putting in a sealed, thick plastic bag and either rolling with a rolling pin or hitting with a meat hammer to crush.
2. Cut up thinner shrimp shells with a chef's knife. Don't crush or cut too small. You can even skip this step if you want, if you are already dealing with broken up shell pieces (like cracked crab).
3. Place in a large roasting pan and roast at 400°F for 10 minutes (this step you can skip, but it greatly enhances the flavor).
4. Put the shells in a large stock pot and add enough water to cover the shells with an inch of water. 2
5. Put the stove temperature on medium high and slowly heat the shells in the water. As soon as you see that little bubbles are starting to come up to the surface, reduce the heat to medium. Do not let it boil. You want to maintain the temperature at just below a simmer, where the bubbles just occasionally come up to the surface. Do not stir the shells. Stirring will muddy up the stock. As the bubbles come up to the surface a film of foam will develop on the surface. Use a large slotted spoon to skim away this foam.
6. Let the shells cook like this for about an hour; skim the foam every few minutes. The foam comes from shells releasing impurities as their temperature increases.3
7. Put the thyme, bay leaves, and parsley in cheese cloth. Secure with kitchen string to make a bouquet garni.4 Once the stock has stopped releasing foam, you can add the wine, onions, carrots, celery, tomato paste, herb bouquet garni, and peppercorns. Bring to a low simmer and reduce heat so that the stock continues to simmer, but not boil, for 30 minutes. If more foam comes to the surface, skim it off.
8. Add salt and remove from heat. 5 Dampen a few layers of cheesecloth and place over a large, fine mesh strainer, over a large pot or bowl.
9. Pour the stock into the strainer. Discard the solids. Either use the stock right away, or cool for future use. If you aren't going to use in a couple of days, freeze (remember to leave some head room at the top of your freezer container for the liquid to expand as it freezes.)