Flavoured fats & thickeners
Confit Fat
Graisse de canard confite · Confit fat is fat—traditionally duck fat, but also goose fat, lard, or beef fat—slowly rendered and infused with aromatics at low temperature, then strained and finished clean. It is both the medium and the product of the classical confit technique: the fat carries the aromatics into the meat during cooking, and the infused fat that remains becomes a highly flavored, shelf-stable foundation fat used throughout the classical repertoire for frying, roasting, finishing sauces, and building dishes. The low-temperature rendering preserves the fat's delicate flavor compounds while fully extracting and concentrating the aromatic character from garlic, thyme, bay, and black pepper.
The formula
5 kg fat : 1 kg aromatics (total)
The aromatics base comprises a 3:1 ratio by weight of onions/carrots/celery to garlic (i.e., 150 g mirepopoix : 50 g garlic), plus a bouquet garni of thyme, bay, and black peppercorns. Salt is not added to the fat itself—seasoning is applied to the meat being confited, not the fat.
Identity
- Rendered from waterfowl or pork fat, never seed or nut oils
- Infused with garlic, thyme, and bay at precisely 80–90 °C, never browned
- Strained through a fine-mesh sieve with cheesecloth—no solid particles remain
- Stored submerged and sealed—no exposure to air or light
- Golden amber in color with a clear, transparent appearance when hot
- Mildly savory, perfumed with garlic and herbs—not overpowering, not flat
Ingredients
| Base | Duck fat (or goose fat, lard, beef fat) | 1 kg raw, trimmed of excess meat and skin; the fat from 4–5 duck legs yields approximately 700–800 g rendered fat |
| Aromatics | Yellow onion, roughly chopped | 100 g—provides sweetness and body to the aromatic infusion; do not caramelize, add raw before rendering begins |
| Aromatics | Carrot, roughly chopped | 30 g—adds subtle sweetness and vegetable character typical of the Southwest French tradition |
| Aromatics | Celery, roughly chopped | 20 g—adds aromatic backbone and balances the richness |
| Aromatics | Garlic, crushed unpeeled cloves | 50 g (4–5 cloves)—the defining aromatic; added once the fat begins to render, to extract flavor without burning |
| Aromatics | Bouquet garni (thyme sprigs, bay leaves, black peppercorns) | 4 sprigs thyme, 2 bay leaves, 10 peppercorns, tied in cheesecloth—added with the garlic, allowed to infuse at low temperature for the full duration |
| Seasoning | Kosher salt | Not added to the fat; the meat being confited carries its own salt cure separately |
Method
- 1Trim duck fat of all meat and sinew, cut into 5 cm pieces, and combine with onion, carrot, and celery in a heavy pot or Dutch oven (cast iron preferred for even heat).Clean trim prevents the fat from acquiring a meaty, off-flavor during rendering. The vegetable aromatics begin slowly releasing their water content and sugars at this stage, building the fat's character from the outside in.
- 2Place the pot over medium-low heat (the fat should begin to slowly melt and release liquid at 60–70 °C). Stir occasionally with a wooden spoon. Cook uncovered, never letting the fat exceed 95 °C, until the fat is fully rendered and the solids (morceaux) are golden and crispy—approximately 45–60 minutes.Low temperature protects the delicate fat from oxidation and burning. The fat must fully render out before garlic and bouquet garni are added—rushing with high heat produces a cloudy, acrid fat with poor flavor.
- 3Add the crushed garlic cloves and bouquet garni to the rendered fat. Maintain temperature between 80–90 °C (a bare shimmer, not a simmer). Infuse for 30–40 minutes.Garlic and herbs are heat-sensitive; high temperature drives off volatile aromatics (diallyl disulfide, thymol, linalool) before they can dissolve into the fat. The slow infusion at 80–90 °C maximizes fat-soluble flavor compound extraction without degradation.
- 4Strain the fat immediately through a fine-mesh sieve lined with cheesecloth set over a clean, dry heatproof container. Discard the solids. Let the fat settle undisturbed for 10 minutes.Straining removes all solid matter that would cause the fat to go rancid during storage. Allowing it to settle lets remaining moisture and fine particles sink, yielding a crystal-clear fat.
- 5Pour the settled, clear fat into a clean glass jar or airtight container, leaving a 5 mm headspace. Seal and label with the date. Cool to room temperature before refrigerating.Airtight sealing excludes oxygen, the primary cause of fat rancidity. Headspace allows for slight expansion. Room-temperature cooling before refrigeration prevents condensation from forming inside the sealed container.
Techniques that matter
Low-temperature rendering (fondage)
Fat is composed of triglyceride molecules; high heat causes hydrolysis and oxidation, producing free fatty acids and off-flavors. Rendering at 85–95 °C preserves the fat's natural smoke point (~190 °C) and aromatic integrity.
Fat-soluble aromatic infusion
The aromatic compounds in garlic (organosulfur compounds), thyme (thymol, carvacrol), and bay (cineole) are lipophilic—they dissolve readily into fat but not into water. The fat acts as a selective solvent, extracting flavor at temperatures well below the boiling point of water.
Straining and settling (défaecation)
Fine straining removes particulate matter (protein fragments, vegetable cells) that accelerates rancidity. Settling allows residual moisture to separate and sink, preventing steam condensation inside storage containers.
Variations & derivatives
Goose fat confit (graisse d'oie confite)Alsace, Southwest France
Richer and more aromatic than duck fat; the classic fat for roasting the Thanksgiving or Christmas goose, and for the Alsace dish oie rôtie. Rendered using the same 5:1 ratio with thyme, juniper, and rosemary.
Southwest garlic confit (confit à la périgourdine)Périgord, Dordogne, France
Intensified version using 2× the garlic (100 g per kg fat) and adding a few sage leaves; the result is deeply savory and perfumed. Used for pommes sarladaises and to finish confit de canard at service.
Provençal confit fat (confit provençal)Provence, France
Uses herbes de Provence (rosemary, lavender, sage, thyme, oregano) in place of bouquet garni; often combined with pork lard for frying. Traditional for confit de légumes (slow-cooked vegetable confit) and for roasting lamb.
Lard confit (confit de lard)Auvergne, Limousin, France
Pork leaf fat rendered with bay, sage, and garlic; the traditional fat of the Massif Central. Used for fricot (Auvergnat pot-au-feu) and to coat charcuterie. Ratios identical—5:1 fat to aromatics.
Beef fat confit (graisse de bœuf confite)Basque Country, Gascony, France
Tallow rendered with garlic, piri-piri chili, and smoked paprika; used in Basque cuisine for frying txuleta (veal chop) and lamb. The chili compounds (capsaicin) are highly fat-soluble and infuse readily.
Used in these dishes
Substitutions
- Duck fat or goose fat → Lard (rendered pork fat) — Acceptable for general frying and roasting; lacks the waterfowl character but performs identically at high heat. Not interchangeable in dishes where duck fat IS the flavor-defining element (pommes sarladaises).
- Duck fat or goose fat → Canola or neutral vegetable oil — Can be used for high-heat frying where the flavor contribution is secondary. Vegetable oils have higher smoke points but no aromatic complexity and no Maillard-enhancing flavor compounds. Never use for finishing or as a sauce component.changes result
- Duck fat or goose fat → Schmaltz (chicken fat rendered with onions) — Traditional in Ashkenazi Jewish cuisine; works well for roasting chicken or potatoes. Different aromatic profile—more savory, less gamey. Acceptable in most applications where duck fat is used as a frying medium.
- Aromatics (bouquet garni and garlic) → Herbes de Provence blend, crushed — In a pinch, replace bouquet garni with 1 tbsp dried herbes de Provence and 2 crushed garlic cloves per kg of fat. Flavor is less nuanced but functional for a weeknight confit.
Troubleshooting
Fat is cloudy or milky after rendering
Water was not fully driven off during rendering; the fat contains emulsified moisture and protein fragments from the fat tissue → Strain the fat and return it to a clean pot. Heat slowly to 110 °C and hold for 10 minutes to evaporate residual moisture. Strain again through cheesecloth and settle. The fat will clear as water fully vaporizes.
Fat has a burnt, acrid smell or dark specks
Rendering temperature exceeded 120 °C, causing the fat to scorch and the remaining solids to burn; this is irreversible → Do not use. Scorched fat has formed acrolein (a harsh aldehyde) and free radicals that are both unpalatable and harmful. Start fresh. For prevention, always render over medium-low heat with a thermometer clipped in place.
Stored fat develops off smell or mold after 2 weeks
Insufficient straining left food particles that harbor bacteria and mold; or container was not airtight and fat was exposed to air and light → If slightly off: melt the fat and strain through cheesecloth plus a coffee filter; heat to 100 °C for 5 minutes to kill microorganisms. If severely off, discard. Always strain fat twice and store in a sealed, darkened container in the refrigerator.
Fat separates or goes solid and chalky in storage
Duck fat naturally solidifies below 14–18 °C—this is normal and not a defect → This is expected behavior. Reheat gently to 30–35 °C to return to a pourable liquid state. The solidification does not indicate spoilage unless accompanied by off smell, discoloration, or mold.