I recently posted an inquiry about making fish stock for bouillabaisse. Heres a report of how it went.
I went out to the coast (Half Moon Bay) to a fish market that sells the local catch. I got a 6 pound halibut (smallest they had) and a 3 pound striped bass (I think). They were beautifully fresh. The fishmonger begrudgingly filleted them out for me, leaving very meaty frames. Once I got home, further butchery was required to completely remove the undesirable bits of gills and guts left behind, and then hack up the carcasses into manageable pieces. (This confirms that I need to get a HUGE stockpot. My merely very big stockpot was too crowded. I had A LOT of fish parts.) Then I rinsed all the parts very well. I had the shells from about a pound of shrimp, which also got the rinse treatment.
I considered the practice of essentially blanching the fish frames as suggesting by Melanie with regard to making poultry stock. I tried that in my last batch of chicken stock and it worked very well. But I decided against it because I feared it would extract too much of the flavor from the fish frames, in light of the short simmer time for fish stock.
So, I sweated diced yellow onion, leek, a small fennel bulb, a stalk of celery, and a handful of halved garlic cloves in butter and olive oil. Added the shrimp shells. Deglazed with Pernod. Added a bouquet garni of fresh thyme, bay leaves, orange peel, fennel seeds, peppercorns, and parsley stems. Then I added all my fish parts, a can of Muir Glen tomatoes, two cups of dry white wine, enough water to fill my pot (about 5 cups), and a pinch of saffron threads and cayenne.
It took forever to come up to a simmer. I think my pot was over-full. Once it did, I maintained a bare simmer for about 40 minutes. I tried not to stir, but couldnt help moving the fish parts around a few times. I skimmed all the scum I could during the simmer, but probably didnt get it all (again, the too-full pot was a problemheads and tails and fins kept poking out). Then I turned it off and let it rest and steep for another 20 minutes.
I strained three times, ending with a very fine strainer lined with cheese cloth. The stock was quite wonderful. Rich, intensely fishy, and fresh tasting without any muddiness. The flavor was multi-dimensional, but fish-forward. None of the supporting flavors asserted themselves individually but just made a platform for the fish.
The bouillabaisse was excellent, but it was all about starting with that stock. Sure, it had the addition of more onion, fennel, leek, tomato, pernod, etc, and that gloriously fresh fish, but the broth was just sublime. Served with an amazing rouille and grilled French bread. Heavenly.
Thanks for all the helpful tips.