Rinse salmon carcasses under cold water and remove any blood spots and discard any gills.

Transfer salmon to a 10- to 12-quart pot.

Wash leeks well and drain.

Add leeks, celery, onions, carrots, garlic, ginger, parsley stems, thyme sprig, coriander seeds, bay leaf, and salt to the pot with salmon.

Pour in dry white wine and cold water.

Bring to a boil, then reduce heat and simmer, uncovered, skimming any foam, for 40 minutes.

Pour stock through a cheesecloth-lined sieve into a 6-quart saucepan.

Boil until reduced to about 9 cups (15 to 20 minutes), skimming any fat from the surface.

Whisk egg whites in a large bowl until foamy.

Crumble reserved shells into whites and slowly whisk in half of the hot stock.

Gradually whisk egg white mixture into the stock in the saucepan and bring to a steady boil over moderate heat, whisking constantly.

Boil, undisturbed, until all of whites rise to top and stock is clear, about 10 minutes.

Remove from heat and let stand 3 minutes.

Pour stock through a cheesecloth-lined sieve into a bowl, then through a paper towel-lined sieve into a 3-quart saucepan.

Reheat and season with salt.

Whisk together creme fraiche and water in a small bowl set over a larger bowl of hot water until it reaches room temperature, then continue whisking until smooth and forms soft mounds.

Serve consomme with dollops of creme fraiche and salmon caviar, garnished with fresh dill sprigs and accompanied by Black Pepper Cornmeal Crisps.