Mirepoix
Mirepoix is a mix of diced onion, carrot, and celery cooked in fat as the flavour base for stocks, soups, sauces, and braises. The classic ratio is 2 parts onion to 1 part carrot to 1 part celery by weight.
What each vegetable brings
Onion (50%) gives sweetness and savoury depth. When cut, its cells release sulfur compounds that are sharp raw but mellow into sweet, rounded flavours with heat. Onions also hold plenty of sugars that brown nicely.
Carrot (25%) adds sweetness and colour. Its carotenoid pigments are fat-soluble, so cooking carrots in butter or oil tints the fat and the finished dish a warm gold.
Celery (25%) contributes a green, slightly bitter, savoury note. Compounds called phthalides give celery its signature aroma and are thought to boost the perception of savouriness in broths.
Together, the mix covers sweet, savoury, and fresh without any one flavour standing out. That is the point: you should taste depth, not "carrot".
Cut size matters
Flavour escapes from cut surfaces. Small pieces release flavour quickly but break down over long cooking; large pieces release it slowly and hold together.
| Cooking time | Cut size | Example |
|---|---|---|
| Under 30 min | 5 mm / 1/4 in dice | Pan sauce, quick soup |
| 30–90 min | 1–2 cm / 1/2–3/4 in | Braise, stew, risotto base |
| 2–8 hours | 5 cm / 2 in chunks | Stocks, pot roast |
For a refined garnish, a much finer cut called brunoise is used instead.
Sweat or brown?
Sweated mirepoix is cooked gently in fat with a pinch of salt over medium-low heat for 8–10 minutes until soft and translucent, with no colour. It gives a clean, sweet base for light soups, white stocks, and velouté.
Browned (or roasted) mirepoix is cooked hotter until deep golden, triggering the Maillard reaction and caramelization. It builds the richer, darker flavour wanted in brown stock, beef stew, and red-wine braises. Some cooks add tomato paste at the end and cook it until rusty, a step called pincé.
Variations
- White mirepoix: onion, celery, leek, parsnip, or mushroom, no carrot, for pale sauces and fish stock.
- Matignon: mirepoix plus diced ham or bacon, cooked in butter and often finished with a splash of wine.
- Cousins: the Cajun holy trinity, Italian soffritto, Spanish sofrito, and German Suppengrün all follow the same aromatic-base idea.
Measure by weight once and you will soon be able to eyeball it: about half onion, a quarter carrot, and a quarter celery.
Questions
What is the ratio for mirepoix?
The classic ratio is 2 parts onion to 1 part carrot to 1 part celery by weight, for example 200 g onion, 100 g carrot, and 100 g celery. For stock, plan roughly 450 g mirepoix for every 4 L of liquid.
How do you pronounce mirepoix?
It is pronounced roughly meer-PWAH. It is named after an 18th-century French duke whose cook popularized it.
What size should I cut mirepoix?
Match the size to the cooking time. Cut 5 mm (1/4 in) dice for quick sauces and soups, 1–2 cm (1/2–3/4 in) for an hour-long braise, and large 5 cm (2 in) chunks for stocks that simmer for several hours.
What is white mirepoix?
White mirepoix swaps the carrot for parsnip, leek, or mushroom so that pale sauces and fish stocks stay ivory instead of turning orange.