Fish and other seafood must be treated differently from meat or chicken when making stock. It cannot be simmered for hours as meat can, or the resulting stock will be bitter, and quite toxic. Fish fumet always contains white wine, but you can make it without and add the wine later, when you are using the stock in a soup or sauce.
For years we have used a scaled and cleaned whole bream or whiting frames as the starting point for fish fumet, but fish frames, particularly reef fish frames are usually available very cheaply from any good fishmonger. I have used red emperor, nanagai, coral trout and even Tasmanian salmon, although the salmon frames give a distinctly salmon taste.
50g butter or a little grapeseed oil
3 sticks celery
1 medium onion, chopped
Sprigs of parsley and thyme
½ bay leaf
½ bottle of dry white wine
Whiting frames and/or scaled and cleaned whole bream, or
1 or 2 white fleshed reef fish frames
Water to cover
In a large stockpot, melt the butter or heat the oil and add the herbs, onions, carrots and celery. Cook over a gentle heat without browning. Add the fish frames and /or the whole bream and allow the frames to saute briefly, turning them to ensure even cooking.
Add the white wine. Cover the pot and increase heat to high. When the wine has reduced to half its previous volume, put in enough cold water to cover the fish. Bring back to the boil, reduce heat, skim and simmer the stock for no more than 30 minutes.
Strain the stock through a coarse sieve, pressing the fish and vegetables with the back of a spoon to release as much flavour as possible. Return fish and vegetables to the pot, add a little boiling water and stir well, but do not cook any further. Strain this into the stock. Discard the frames and the vegetables and re-strain the stock through a fine sieve.
Refrigerate stock so that the fats rise to the surface, then skim. (Fish frames do contain fat.)
Fish stock will keep well in the freezer.