Noble Notations
Recipes / Demi-Glace
Preparationrevision 1via 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.

EquipmentChina capEquipmentA rigid cone-shaped metal strainer with perforated holes. Coarser than a chinois; used to strain stocks and to press solids through with a ladle.CuisineFrenchCuisineThe codified European tradition of stocks, mother sauces and precise knife work — the source of most professional kitchen vocabulary.TechniqueRoastingTechniqueDry heat, usually uncovered and at higher temperature than baking, to brown a surface while the interior cooks through.CourseSauceCourseA liquid or emulsion built to dress something else. Unlike a condiment it is usually applied in the kitchen, not at the table.TextureSilkyTextureSmooth and coating on the tongue, with no perceptible grain — usually from emulsification or fine straining.TechniqueClarificationTechniqueRemoving suspended solids from a liquid to leave it transparent — by raft, straining, gelatin filtration or settling.EquipmentFine-mesh sieveEquipmentA woven wire strainer fine enough to catch spice grit and coagulated protein — the last pass before a liquid is called clear.TechniqueReductionTechniqueSimmering a liquid to evaporate water, concentrating flavour and thickening through dissolved solids rather than added starch.

Why this revision

Transcribed from the archive research note into an executable preparation.

Method

12 steps

Roast

  1. 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.

    45 min232 °CRoasting

  2. 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.

    20 min204 °C

  3. 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

  1. Simmer the stock 12 hours, then strain through a China cap lined with cheesecloth to take out the large particulates.

    12 hSimmering

  2. 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.

    71 °C

  3. Pass through a colander lined with damp coffee filters for final optical clarity.

Espagnole

  1. Whisk the flour into the clarified butter and cook to the hazelnut stage, about 121 °C. Fold in the caramelised mirepoix.

    121 °C

Reduce

  1. Stage one: 4 hours at 96 °C, reducing by 30%, with a sachet of dried mushroom aromatics.

    4 h96 °CReduction

  2. Stage two: 2 hours at 90 °C to 50% reduction, adding a cup of Pedro Ximénez sherry.

    2 h90 °C

  3. 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.

    1 h85 °C

Finish

  1. Suspend the kombu in the reduction for the final 30 minutes to draw out glutamates without picking up marine notes.

    30 min

Store

  1. 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.

    10 °C

Notes

1
WarningTime 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

The science

1

What is actually happening in the dish, and why the techniques work.

scienceWhy 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.