Remouillage — 'rewetting' — is the stock made from bones that have already been used for a first stock. It is the thrifty, essential practice of extracting every molecule of flavour and gelatin from bones that still have something to give. In any professional kitchen that makes its own stocks, remouillage is what runs continuously on the back burner: not as rich as the first extraction, but far too valuable to waste. The technique is simple. After straining a first extraction of fond brun or fond blanc, return the bones and mirepoix to the stockpot. Cover with fresh cold water. Bring to a gentle simmer and cook for 4-6 hours (brown stock bones) or 3-4 hours (white stock bones). Skim as for the first extraction. Strain. The resulting liquid will have approximately 40-60% of the first stock's gelatin content and flavour intensity. It will be lighter in colour and body, but it is not weak — it is simply less concentrated. The distinction matters: a remouillage that has been reduced by half approaches the intensity of a first-extraction stock at full volume. Remouillage has three primary uses. First: as the water for the next batch of first-extraction stock. Instead of starting with plain water, use remouillage. This creates a stock of extraordinary depth — each batch builds on the one before it. Second: as a braising liquid where full-strength stock would be too intense. Third: reduced by three-quarters, as an economical glace de viande for sauce mounting. In Escoffier's Brigade system, remouillage was the responsibility of the most junior cook — it required no skill beyond patience and attention to simmering temperature. But the stock it produced was the hidden foundation of the kitchen's sauce output. A kitchen that throws away used bones is a kitchen that does not understand economy, and economy is where French cooking begins.
1. Fresh cold water on used bones — never add to the existing stock. 2. Simmer time is shorter than first extraction — the bones have already given their most accessible collagen. 3. The result has 40-60% of first stock's body — it is not waste. 4. Best use: as the water for the next first-extraction stock, building depth over cycles. 5. This is the practice that separates professional kitchens from home cooking.
Keep a rolling remouillage system: every time you make stock, remouillage the bones; every time you make stock again, use the previous remouillage as your water. After three cycles, even a modest stockpot produces liquid of remarkable depth. Label your remouillage with the extraction number — 'R1' (first remouillage), 'R2' (second) — to track quality. By R3, the bones have given everything and should be discarded.
Boiling instead of simmering, which extracts bitter compounds from bones that have already been stressed. Cooking too long — beyond 6 hours, used bones begin to release calcium phosphate, which makes the stock chalky. Discarding remouillage because it seems 'weak' — it is lighter, not weak. Not skimming, which makes an already delicate stock cloudy.
Provenance originals