7.1 Stock Foundations & Mirepoix

7.1 Stock Foundations & Mirepoix

Quick Answer: Build stock from clean bones, balanced mirepoix, and cold water; extract gently so collagen becomes gelatin without clouding; know remouillage as a second pull and nappé as a coating thickness; skim and strain for clarity.

Major Work Activity D (Stocks, broths and soups) on the Red Seal Cook exam opens with Task D-13: prepare stocks and broths. Exam items test whether you understand why a stock gels, why it went cloudy, how much mirepoix to use, and what to do with bones after the first extraction—not whether you can recite a restaurant brand of base.

What a Stock Is

A stock is a flavoured liquid made by simmering bones (and sometimes meat trim), aromatic vegetables, and seasonings in water, then straining. Bones contribute collagen, which converts to gelatin during moist heat. Gelatin gives body: a good cooled meat stock often sets lightly; a thin, watery stock will not coat sauces or soups well.

Flavour comes from bones, connective tissue, meat scraps, and aromatics. Colour comes from the ingredients and from browning (Maillard reactions) when bones and vegetables are roasted for brown stocks. Stock is usually lightly seasoned or unsalted so it can be reduced, salted later, or used across many recipes without over-salting.

Broth (covered deeply in 7.2) is related but typically meat-forward, more fully seasoned, and often served as a finished sipping liquid. On exam scenarios, if the cook needs a building-block liquid for sauces and braises, think stock; if guests will drink it as soup, think broth—though kitchens blur the terms in casual speech.

Bones: Selection and Prep

Choose bones appropriate to the stock:

Remove excess fat and blood if present. For many white meat stocks, blanching bones (cover with cold water, bring to a boil, drain, rinse) removes impurities that would otherwise foam heavily and muddy flavour. For brown stocks, roast bones until deep mahogany—burnt black bones taste bitter and cannot be fixed by more water.

Fish bones need special care: remove gills (bitter), rinse thoroughly, and avoid long simmering that turns the liquid grey and fishy. Shellfish shells (shrimp, lobster) are roasted or sautéed for bisque bases more often than for classic white fish fumet.

Water, Ratios, and Aromatics

A practical training starting point many Canadian culinary programs teach is roughly 1 kg bones to about 4 L water, adjusted so bones are covered with a little headspace. Too little water scorches and over-concentrates; too much water makes a thin, pale extraction that never develops body even after hours.

Mirepoix is the aromatic vegetable foundation. The classical weight ratio is:

A common rule of thumb is about 10% mirepoix relative to bones by weight (for example, 100 g mirepoix per 1 kg bones), plus a bouquet garni or sachet d’épices (parsley stems, thyme, bay, peppercorns). Garlic, tomato product, mushroom trim, or leek greens appear in house recipes—know the classical core first, then variations.

White mirepoix (onion or leek, celery, sometimes parsnip; little or no carrot) protects the pale colour of white stocks and blond sauces. Matignon or other aromatic cuts appear in some classical texts; for Red Seal purposes, master standard mirepoix ratios and when to withhold carrot.

Cut mirepoix to a size that matches cook time: larger chunks for long beef stocks, smaller for short fish fumets so aromatics extract without turning to mush that clouds the liquid.

Remouillage

Remouillage (literally “rewetting”) means covering already-extracted bones with fresh water and simmering again to pull remaining flavour and gelatin. The second liquid is weaker than the first stock. Uses include:

• Combining with the first stock for a fuller yield before reduction
• Starting a weaker base for soups where intense stock would be too heavy
• Further reduction into glazes when the first stock has already been reserved for premium sauces

Exam trap: Remouillage is not equal to a properly made first extraction. If a question asks for maximum body and clarity for consommé or demi-glace work, start with a well-made primary stock—not a thin second wetting alone.

Nappé and Body

Nappé (from napper, to coat) describes a consistency that coats the back of a spoon in a thin, even sheet. Drag a finger across the spoon: a clean path that holds its edges indicates useful thickness for many sauces and reduced stocks. Stocks themselves may be thinner than a finished sauce; reduction concentrates gelatin and flavour until nappé is reached.

Body also shows when chilled stock gels. A soft gel signals adequate collagen extraction. A stock that stays watery when cold was under-extracted (too much water, too little connective tissue, too short a simmer) or made mostly from meat without enough bone.

Clear vs Cloudy

Clarity is a process outcome:

Cloudy stock can still taste good for rustic soups and stews. For consommé, aspic, and clear broth presentation, clarity matters. Clarification techniques (egg-white raft) belong to soup cookery in 7.3; the foundation is still a carefully made, skimmed stock.

Workflow Habits That Score Points

1. Mise en place: bones prepped, mirepoix cut, sachet tied, skimmer and chinois ready.
2. Degrease: chill and lift fat, or ladle carefully while hot for immediate use.
3. Cool safely: Canadian kitchens treat 4°C–60°C as the danger zone—cool large stock batches in ice baths or shallow pans before refrigeration; do not leave a deep pot of stock on the counter for hours.
4. Label, date, and FIFO; freeze in usable units if not using within a few days per house policy.
5. Taste for bitterness (burnt roast, overcooked fish), weakness (remouillage alone), or salt (if someone seasoned early).

Red Seal scenarios often ask why a stock is cloudy, what remouillage is for, how mirepoix is proportioned, or what nappé looks like on a spoon. Answer with extraction science and process control.