How to Make Vegan Demi-Glace

I learned to make demi-glace at twenty-three, in a small French bistro kitchen in the 11th arrondissement of Paris where I worked as a commis for a single summer between marketing jobs. The chef was a man named Henri who had trained at Le Chapon Fin in the 1980s and considered demi-glace the foundation of the entire kitchen. He taught me the traditional method first — brown veal stock, slow reduction, the works — and then, on the third week, asked me to make a vegetarian version for a regular customer who had stopped eating meat.

The first attempt was a disaster. I had reduced a mushroom stock for two hours and produced something that was, generously, a watery mushroom broth. Henri tasted it. He said, in his slow Burgundian French: “C’est un bouillon. Ce n’est pas une demi-glace.” That’s a broth. It’s not a demi-glace.

What he taught me over the next month — between his actual paying customers, in the spare hours between lunch and dinner service — was the principle that made the vegetarian version work. The traditional demi-glace gets its body from collagen breaking down out of veal bones over hours. The vegetarian version, with no bones, has to get its body from the natural pectin and starches of long-cooked roasted vegetables, combined with the careful reduction of a deeply roasted mushroom stock. Same target. Different mechanism. The key, Henri said, was the roasting — every ingredient that goes into the stock must be roasted dark first. The Maillard reaction is doing the work the bones were doing.

The recipe below is the one I have arrived at after fifteen years of refinement. It is a five-hour project. It produces about 2 cups of demi-glace from 4 liters of starting liquid — a 87% reduction. The result is glossy, mahogany-colored, with the viscosity of light cream when warm and the body of soft jelly when cold. It coats the back of a spoon. It leaves a trail when dragged through. It transforms whatever dish you add a tablespoon of it to.

The recipe

This makes about 2 cups (480 ml) of finished demi-glace.

The roasted vegetable base

• 2 lbs (900 g) king oyster mushrooms, large chunks
• 1 lb (450 g) cremini mushrooms, halved
• 2 large yellow onions, halved
• 2 large carrots, in 2-inch chunks
• 2 celery stalks, in 2-inch chunks
• 1 whole head garlic, halved horizontally
• 1/3 cup (80 ml) olive oil
• 1 tsp fine sea salt
• 3 tbsp tomato paste

The aromatics

• 1 bottle (750 ml) red Burgundy wine — yes, a whole bottle
• 4 liters (about 17 cups) cold water
• 3 tbsp soy sauce
• 2 tbsp vegan Worcestershire sauce
• 8 sprigs fresh thyme
• 4 sprigs fresh parsley
• 4 bay leaves
• 2 tsp black peppercorns

The finish

• 2 tbsp arrowroot or cornstarch (optional, for additional body)
• 2 tbsp cold water

The method

Stage 1 — Roast everything dark (60 minutes)

Heat oven to 425°F (220°C). On two large sheet pans, spread the mushroom chunks, halved onions, carrots, celery, and garlic. Drizzle with olive oil. Sprinkle with salt. Toss to coat. Roast for 45 to 60 minutes, stirring twice, until everything is deeply browned — almost charred at the edges. The mushrooms should be the color of dark chocolate. The onions should be black at the cut sides. The carrots should be deeply caramelized.

This is the most important step in the entire recipe. Under-roasted vegetables produce a thin, pale demi-glace. Deeply-roasted vegetables produce the mahogany sauce we’re after.

Stage 2 — Toast the tomato paste (3 minutes)

Add the tomato paste to one of the hot sheet pans and stir to coat the roasted vegetables. Return to the oven for 3 more minutes — just long enough for the tomato paste to darken from red to brick. Pull out.

Stage 3 — Deglaze with wine (90 minutes)

Transfer all the roasted vegetables, garlic, and tomato paste to a large stockpot (8+ quart). Pour in the full bottle of red wine. Bring to a vigorous simmer over medium heat. Cook 30 minutes — the wine should reduce by about a third.

Then add the cold water, soy sauce, Worcestershire, thyme, parsley, bay leaves, and peppercorns. Bring to a gentle simmer — never a hard boil. Skim any foam that rises. Simmer for 3 hours at a bare tremble, uncovered. The volume will reduce by about 40%.

Stage 4 — First strain (10 minutes)

Pour the entire pot through a fine-mesh sieve into a clean pot, pressing lightly on the solids to extract their juices. Discard the solids. You should have roughly 2 liters of strained liquid — deeply colored, intensely flavored, but still thin.

Stage 5 — The slow reduction (90 to 120 minutes)

Return the strained liquid to the stove at a bare simmer. Reduce slowly — never aggressively — for 90 minutes to 2 hours, watching the volume and the viscosity. The liquid will reduce from 2 liters down to about 500 ml. The final test is the coating-the-spoon test: dip a metal spoon into the liquid and draw a finger across the back of the spoon. If the demi-glace holds the line you’ve drawn for a few seconds before closing back, you’re done. If it closes immediately, reduce longer.

Stage 6 — Optional final body boost

If after 2 hours of reduction the demi-glace is concentrated and tasty but not thick enough, you have two options. Option A: keep reducing — patience always wins. Option B: whisk together 2 tablespoons arrowroot or cornstarch with 2 tablespoons cold water into a slurry. Whisk into the simmering demi-glace gradually. It will thicken within 60 seconds. This option is faster but slightly compromises the texture — true demi-glace gets its body from natural reduction, not starch. Use this option only if you’ve genuinely over-reduced and lost too much volume.

Stage 7 — Strain once more, cool, store

Strain the finished demi-glace through a fine-mesh sieve one final time (this catches any tiny solids that have settled out during reduction). Cool to room temperature. Transfer to clean jars or to ice cube trays for portioning.

Keeps 1 month in the fridge, 1 year in the freezer.

How to use it

As a finishing sauce

Reduce a tablespoon of demi-glace in a hot sauté pan with 1 teaspoon of cold vegan butter. Swirl. Pour over a seared mushroom steak, a roasted carrot, a piece of grilled cauliflower. Done in 30 seconds. Restaurant-grade.

As a pan sauce base

After searing whatever you’re cooking, pour off excess fat. Add 1/4 cup of red wine to the hot pan. Scrape the bottom. Reduce by half. Add 2 tablespoons of demi-glace. Swirl in 1 tablespoon cold vegan butter off the heat. Spoon over the protein. Eighty seconds total. The chef-grade pan sauce.

As a depth-builder

Add 2 to 3 tablespoons to any stew, braise, or soup that needs more body and umami. This is the move that takes a Tuesday-night soup from fine to restaurant-grade. The demi-glace dissolves immediately and disappears into the dish, leaving only its depth behind.

As a glaze

Reduce 1/4 cup of demi-glace with 1 tablespoon maple syrup until syrupy. Brush over roasted vegetables in the last 5 minutes of their cooking time. The glaze lacquers as it cools — glossy, deep brown, with a faint sweet-savory finish.

The five mistakes to avoid

1. Under-roasting the vegetables. Roast until almost charred. The Maillard reaction is doing the work the bones do in traditional demi-glace. Pale roast equals pale demi-glace.

2. Boiling instead of simmering. Aggressive boiling produces a cloudy, sharp broth instead of a clean, concentrated one. Bare tremble throughout.

3. Skipping the wine. The wine adds essential character — tannin, acid, depth. Substituting with more water produces a flatter result. If wine is genuinely unavailable, use 2 tablespoons of balsamic vinegar plus 2 tablespoons of dry sherry plus 600 ml additional water — close but not equivalent.

4. Stopping the reduction too early. Demi-glace at 1.5 liters of finished volume is just concentrated stock. Demi-glace at 500 ml is the actual sauce. Keep reducing until the spoon-coat test passes.

5. Using starch when patience would have served. A slurry-thickened demi-glace is a backup option, not the goal. The texture and shelf-stability of a properly-reduced demi-glace exceed a starched one. Reduce slowly. The body will come.

Why this is worth a Saturday afternoon

Two cups of demi-glace, made on a Saturday afternoon, will improve the cooking you do for the next two months. Every braise, every pan sauce, every roasted vegetable plate gains a layer of depth from a tablespoon of demi-glace folded in at the right moment. It is the most consequential five-hour investment you can make in your kitchen.

Henri, my mentor in that small Paris bistro, used to say: “Sans demi-glace, on cuisine. Avec demi-glace, on cuisine sérieusement.” Without demi-glace, you cook. With demi-glace, you cook seriously.

Make this once. Freeze in cubes. Use everywhere. The transformation in your cooking — particularly in long-braised dishes like the boeuf bourguignon and coq au vin on this site — will be immediate and lasting.