ResearchComponent of
Beef Wellington: Moisture Control as the Whole Problem
The red wine reduction served with a Wellington is built on this.
Demi-Glace
Recipes · Demi-Glace
First revision · 04 SEP 2026
PreparationFirst revisionVia import
Demi-Glace
A 48–72 hour reduction, done properly
Classical demi-glace with a dual-bone foundation, triple clarification and a staged reduction. A preparation other recipes pull in rather than a dish.
Batch
Why the first revision
Transcribed from the archive research note into an executable preparation.
Tap a step to cross it out0 / 12 done
Roast
3 steps-
Arrange the bones in a single layer on rack-lined sheet pans and roast at 232 °C for 45 minutes to develop the Maillard crust.
-
Brush the bones with tomato paste thinned with the vinegar and return to a 204 °C oven for 20 minutes.
Pyrolising the sugars in the paste is what builds the crust.
Time 20 minTemp 204 °C -
Deglaze each sheet pan in turn with a cup of water, scraping the fond into a reserve bowl. Repeat until the pans run clear.
Clarify
3 steps-
Simmer the stock 12 hours, then strain through a China cap lined with cheesecloth to take out the large particulates.
Time 12 hWork Simmering -
Cool to 4 °C, add ice and lightly beaten egg whites, and bring slowly back to 71 °C so a protein raft forms and traps the fine impurities.
Temp 71 °C -
Pass through a colander lined with damp coffee filters for final optical clarity.
Espagnole
1 step-
Whisk the flour into the clarified butter and cook to the hazelnut stage, about 121 °C. Fold in the caramelised mirepoix.
Temp 121 °C
Reduce
3 steps-
Stage one: 4 hours at 96 °C, reducing by 30%, with a sachet of dried mushroom aromatics.
-
Stage two: 2 hours at 90 °C to 50% reduction, adding a cup of Pedro Ximénez sherry.
Time 2 hTemp 90 °C -
Stage three: 1 hour at 85 °C to 70% reduction, finishing with black garlic purée. Stir only with a flat-edged wooden spatula so nothing scorches.
Time 1 hTemp 85 °C
Finish
1 step-
Suspend the kombu in the reduction for the final 30 minutes to draw out glutamates without picking up marine notes.
Time 30 min
Store
1 step-
Cool to 10 °C within 20 minutes in an ice bath, portion into jars, and freeze at −30 °C so the gelatin matrix vitrifies instead of forming ice crystals.
Temp 10 °C
Notes
11
WARNING Time is the actual ingredient
This is a 48–72 hour commitment. Every shortcut in it trades away the thing that makes it worth doing.
Related
5RecipeReferenced by
Sauce Périgueux Spaghettini with Seared Duck Breast
A demi-glace truffle sauce on spaghettini, with cold-pan duck breast and a bitter leaf salad
Sauce Périgueux is the classical French truffle sauce. It is built on demi-glace, not on butter.
RecipeReferenced by
South African Pepper Steak Pie
Shin, oxtail and tendon braised in merlot and set in their own gelatin, frozen as pucks and baked in individual puff pastry pies.
The South African garage pie, made as individual pies in 120 mm foil tins.
RecipeReferenced by
Pan-Seared Duroc Pork Chop, Demi-Glace and Mustard Sauce
Dry-brined 2.5 cm chops, fat cap rendered, turned every 30 s, thyme-garlic butter baste
Bone-in Duroc chops, 2.5 cm thick. Dry-brine with salt and MSG for 45 min. Render the fat cap on its edge. Sear in the pan and turn every 30 s to 55 °C.
PreparationReferenced by
Mixed-Bone Brown Stock
Roasted beef, marrow, chicken and lamb bones held at a light simmer overnight, with no salt
A brown stock made for the braise of the South African pepper steak pie. Beef bones and marrow bones roast first.
Literature
4The pattern
reduced stockThe plain idea under this dish. Cook it with what you have. The full recipe is on the Method tab.
roasted gelatin-rich bones glazed with tomato paste + water, simmered long and strained + brown roux with caramelised mirepoix + aromatics in a slow staged reduction
Other dishes with this pattern: reduced stock.
The parts
4base
3 lb beef marrow bones, 2 lb veal knuckles, 1 lb oxtail. Roasted, then brushed with 6 oz tomato paste thinned with 2 oz red wine vinegar and roasted again.
Marrow gives fat and mouthfeel. Veal knuckle gives gelatin. Oxtail gives concentrated meatiness. The roast and the tomato glaze give the brown crust.
liquid
Water: a cup of water to deglaze each roasting pan, then the stock simmered for 12 hours. The record does not give the total volume of water.
Water dissolves the browned residue and extracts the gelatin from the bones.
binder
Brown roux: 180 g Wondra flour cooked in 1 lb clarified butter to the hazelnut stage, about 121 °C.
The roux is the espagnole part of the sauce. It adds body and a toasted taste.
aromatics
2 cups mirepoix caramelised separately in duck fat (folded into the roux). A sachet of dried mushroom aromatics, a cup of Pedro Ximénez sherry and black garlic purée in the reduction stages. A 4 inch piece of kombu for the last 30 minutes (optional).
These add sweetness, roasted depth and glutamate as the stock reduces.
The basic method
7- Put the bones in one layer on racks in roasting pans. Roast at 232 °C for 45 min.
- Brush the bones with the tomato paste thinned with the vinegar. Roast at 204 °C for 20 min more.
- Deglaze each pan with a cup of water. Scrape all the brown residue into a bowl.
- Simmer the bones and the pan residue in water for 12 hours. Strain the stock through a strainer lined with cheesecloth.
- Cook the flour in the clarified butter until it is hazelnut brown, about 121 °C. Fold in the caramelised mirepoix.
- Reduce slowly in three stages: 4 hours at 96 °C with the mushroom sachet, to 30 % reduction. Then 2 hours at 90 °C with the sherry, to 50 % reduction. Then 1 hour at 85 °C with the black garlic, to 70 % reduction. Stir with a flat wooden spatula so nothing burns.
- Cool to 10 °C within 20 minutes in an ice bath. Put it in jars. Freeze it at −30 °C.
What the full recipe adds
The full recipe adds a triple clarification after the 12 hour simmer. Each pass is a different mechanism: a cheesecloth strain removes large particles, a protein raft of egg white (stock cooled to 4 °C, then brought slowly back to 71 °C) traps fine particles, and damp coffee filters give final optical clarity. It also explains why each bone stays: dropping one is a real loss, not a simplification. It sets the exact temperature of each reduction stage and adds kombu for the last 30 minutes to add glutamate without a sea taste. Fast cooling and freezing at −30 °C make the gelatin set as a glass, not as ice crystals. The record calls the whole job a 48–72 hour commitment, and warns that every shortcut trades away the thing that makes it worth doing.
The science
1What is actually happening in the dish, and why the techniques work.
M1
Why each layer exists
The dual bone foundation is doing three separate jobs: marrow for fat and mouthfeel, veal knuckle for gelatin, oxtail for concentrated meatiness. Dropping any one of them is a real loss rather than a simplification. The triple clarification is likewise three different mechanisms — mechanical, protein raft, adsorption — not the same step done three times.