Stocks & broths
glace de volaille
glace de volaille · A highly concentrated brown stock made from roasted poultry carcasses, reduced to a syrupy, paint-like consistency. When cold it should form a trembling gelatinous mass; when reheated it coats a spoon with a glossy, intensely savory film. It is the poultry-specific analogue of demi-glace and serves as the foundational finisher for virtually all chicken-based sauces and braises in classical French cuisine.
The formula
15 parts finished brown stock : 1 part finished glace (by weight, 1.5 L stock → ~100 g glaze)
Begin with ~1.5 L finished brown chicken stock per 100 g finished glace. A properly made glaze should coat the back of a spoon in a thick, glossy layer; when cold it trembles when the vessel is shaken.
Identity
- Made from roasted poultry carcasses — raw bones roasted at 200–220 °C until mahogany, never from pre-cooked scraps
- Reduced to gelatinous consistency when cold — contains approximately 1.5–2% dissolved collagen-derived gelatin, sufficient to form a trembling gel
- Contains no roux, flour, or starch thickener — concentration is achieved entirely by evaporation
- Always finished by straining through a fine-mesh conical strainer lined with damp cheesecloth
- Seasoned with salt only at service, never during reduction — mineral concentration would become unbearable
Ingredients
| Base | poultry carcasses and raw bones (chicken, pheasant, guinea fowl) | Necks, backs, wings, and carcasses. Fresh (not previously cooked) bones roasted to develop the Maillard color. Restaurant scraps from cooked birds lack sufficient collagen and color. |
| Aromatics | mirepoix (onion, carrot, celery in 2:1:1 ratio by weight) | Classic ratio by weight: 2 parts onion, 1 part carrot, 1 part celery. Use roughly 150–200 g mirepoix per kg of bones. |
| Acid | tomato product (tomato paste preferred) | Adds acidity to lift mineral flavors from bones and contributes the deep mahogany color. Tomato paste at 1–2 tbsp per kg bones is most common. |
| Liquid | cold water | Sufficient to cover bones by 5–8 cm. Start cold to extract maximum gelatin and allow impurities to rise as foam. |
| Aromatics | bouquet garni (thyme, bay leaf, parsley stems) | Classic fines herbs group. Approximately 1 bay leaf, 3–4 sprigs thyme, small bunch flat-leaf parsley per kilogram bones. |
| Seasoning | black peppercorns | 4–6 whole peppercorns, crushed lightly. Added whole; removed with aromatics at straining. |
| Seasoning | egg white (optional fining agent) | 1–2 egg whites per liter of cold stock, whisked in and brought gently to 60–65 °C to coagulate and clarify impurities. |
Method
- 1Roast poultry bones and mirepoix at 220 °C (425 °F) for 45–60 minutes, turning once, until deeply browned on all surfaces.The Maillard reaction between amino acids and reducing sugars creates the characteristic brown color and hundreds of flavor compounds — including pyrazines and furans — that distinguish a brown stock from a white one. Insufficient color yields a flat, grey finished glace.
- 2Transfer roasted bones and vegetables to a stockpot. Deglaze the roasting pan with a small amount of cold water, scraping up all caramelized bits (fond), then pour into the pot.The fond contains the most intensely flavored compounds from the roast. Deglazing immediately captures them before they oxidize. This is non-negotiable in classical cooking.
- 3Add cold water to cover the bones by 5–8 cm, then add tomato product and bouquet garni. Bring to a full boil over high heat, then immediately reduce to the gentlest possible simmer — a few lazy bubbles breaking the surface.A rapid boil bruises proteins, emulsifies fat, and clouds the stock. A bare simmer allows controlled extraction of collagen into gelatin while keeping the stock crystal-clear. Skim thoroughly during the first 20 minutes.
- 4Simmer uncovered for 4–6 hours. Strain through a fine-mesh strainer lined with damp cheesecloth. If using egg-white fining, whisk egg whites into cold stock, bring slowly to 60–65 °C while stirring, then strain.4–6 hours extracts maximum collagen without over-extracting bitter proteins from the marrow. Egg-white fining: proteins form a lattice that traps suspended particles and fat droplets, producing a clear stock.
- 5Return strained stock to a wide, heavy-bottomed sauté pan or rondeau. Reduce over medium-low heat, skimming every 15 minutes, until the liquid coats a spoon in a thick, glossy layer.The wide surface area of a rondeau maximizes evaporation. As volume decreases 15-fold, flavor compounds and gelatin concentrate proportionally — at sufficient gelatin content the stock coats surfaces. Skimming removes residual fat and protein.
Techniques that matter
Maillard reaction
Roasting bones and mirepoix at 220 °C triggers the Maillard reaction, producing brown melanoidin pigments and savory flavor compounds absent from white stocks. This is the chemical basis of all brown stocks and the glace's deep color.
Collagen-to-gelatin hydrolysis
Extended simmering at 85–95 °C in slightly acidic conditions (tomato provides this) hydrolyzes collagen triple-helices into individual gelatin molecules. Gelatin gives the finished glaze its body, mouthfeel, and trembling gel texture when cooled.
Fond development and deglazing
The caramelized drippings (fond) stuck to the roasting pan represent a flavor concentration more intense than the bones themselves. Systematic deglazing with cold liquid captures these compounds — discarding the pan residue means discarding flavor.
Reduction concentration
As volume decreases proportionally, all dissolved solids — gelatin, minerals, Maillard compounds, glutamates — concentrate. A 15:1 reduction creates an intensely savory, unctuous glaze whose flavor exceeds the sum of its starting ingredients.
Fining (optional clarification)
Egg-white proteins denature and form a porous coagulation lattice at 60–70 °C. Suspended solids and fat droplets become trapped in this lattice as it rises, leaving the liquid brilliantly clear. Classic technique for refined stocks.
Variations & derivatives
glace de canardFrance
Duck carcass-based equivalent. The higher fat content and darker meat bones produce a richer, more gamey finished glace. Used to finish sauce bigarade and canard à l'orange.
glace de gibierFrance
Game bird glace from pheasant, partridge, or quail carcasses. Often includes juniper berries (2–3 crushed) and a splash of red wine. Used as base for sauce chevreuil.
demi-glaceFrance
The classical meat equivalent: made from roasted veal or beef bones, reduced with brown stock and espagnole sauce. Strictly speaking, demi-glace is 50% brown stock + 50% espagnole, reduced to coating consistency. Glace de volaille is often substituted when veal is unavailable.
glace de homardFrance
Lobster reduction — shells roasted in butter, then reduced with white wine and fish stock to a potent, briny glaze used in haute seafood preparations.
Used in these dishes
Substitutions
- glace de volaille → demi-glace (veal) — Demi-glace is the classical meat equivalent with identical use and similar body. In modern restaurant practice, demi-glace often replaces glace de volaille in chicken dishes when time-pressed. 1:1 substitution ratio.
- glace de volaille → equal parts brown chicken stock + 50% tomato paste, reduced together — A rapid substitute made by reducing good brown chicken stock with tomato paste until coating. Lacks the depth of roasted-bone Maillard compounds but is acceptable in emergency.changes result
- glace de volaille → jus de rôti (pan drippings reduced with stock) — The natural juices from a roasted chicken, deglazed and reduced with chicken stock, produce a simplified jus. Requires a freshly roasted bird — not equivalent to the real thing.changes result
Troubleshooting
The finished glace is thin and watery when cooled — does not form a gel
Insufficient simmering time or bones that were already parcooked (restaurant scraps often are). Collagen extraction requires 4+ hours at gentle simmer. → Return to simmer with a splash of water, add 50 g fresh chicken feet or pork trotters per liter of stock (both are collagen-rich), and continue reducing. Alternatively, dissolve powdered gelatin in warm stock.
The glace tastes bitter or has a harsh, metallic edge
Reduced at too high a temperature, causing caramelization of sugars and degradation of proteins. Also caused by insufficient skimming — impurities accumulate and concentrate. → Add 50–100 ml cold water per liter of glaze, re-strain through cheesecloth, and resume reduction over lower heat. If severely burned, discard and begin again.
The glace has a greasy, waxy mouthfeel and dull surface sheen
Fat was not adequately removed before or during reduction. Fat droplets become trapped in the gelatin matrix, creating an unpleasant mouthfeel and preventing proper gloss formation. → After final straining, refrigerate the stock overnight. Remove the solidified fat layer from the surface. Reheat gently and reduce to glaze consistency.
The stock is cloudy and murky before reduction begins
Boiling occurred, or insufficient skimming during the first 30 minutes. Aggressive boiling emulsifies fat and suspends protein particles. → Fining with egg whites: whisk 1–2 egg whites per liter of cold stock, then bring slowly to 60–65 °C while stirring. The whites will coagulate into a raft, trapping impurities. Strain through cloth before reducing.