Fumet de Poisson — Fish Stock Technique

Ingredients

• 1000 g white fish bones, sole, turbot, or halibut only; gills and blood removed, rinsed thoroughly
• 500 g fish trimmings, heads (no gills), skin, collars from same white fish varieties
• 1 litre cold water
• 250 ml dry white wine, Sauvignon Blanc or Albariño
• 1 medium yellow onion, thinly sliced
• 1 celery stalk, thin sliced
• 80 g white mushroom stems, sliced, or dried porcini if available
• 1 bay leaf, fresh
• 3 sprigs fresh thyme
• 5 white peppercorns, whole
• 5 ml lemon juice
• Maldon sea salt, to taste

Method

1. 1
   Place fish bones and trimmings in cold water in heavy-bottomed saucepan; gently heat to just below simmer, approximately 15 minutes — aim for temperature of 65–70°C, never boiling.
2. 2
   As stock approaches temperature, skim white foam and impurities that rise to surface using fine skimmer or slotted spoon; discard completely — clear broth requires patient skimming.
3. 3
   Add sliced onion, celery, mushroom stems, bay leaf, thyme sprigs, and white peppercorns; maintain gentle simmer at 65–70°C for 20 minutes exactly — do not exceed, as extended cooking extracts bitter compounds from bones.
4. 4
   Strain stock through fine-mesh sieve lined with damp cheesecloth; do not press solids; discard.
5. 5
   Cool to room temperature; season with lemon juice and Maldon salt to taste.
6. 6
   Use immediately, refrigerate up to 2 days, or freeze up to 2 months — this delicate stock forms the base for beurre blanc, sauce normande, and velouté preparations.