Skip to main content
Main

Onion Soup

A savory soup made from onions, butter, flour, water, salt, sugar, egg yolks, cream, served with toasted bread.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 9 ingredients
Jump to recipe ↓

Why it works: Butter and cream are a kitchen classic. They rank in the top 8% of all ingredient pairs, and cooks put them together in 41,516 recipes. Both carry delta-dodecalactone, which smells sweet, creamy. The science ↓

Onion Soup

Ingredients

Directions

Make the soup

  1. Fry the onions in butter or dripping until brown.

  2. Stir in the flour with the onions.

  3. Add the hot water and stew the onions until tender.

  4. Add salt and sugar.

  5. Strain the soup into a hot tureen.

Finish and serve

  1. Quickly stir in the egg yolks and cream.

  2. Place the hot toast in the soup tureen before pouring in the soup.

Recipe from a historical cookbook (Internet Archive).

Transcribed from a scanned cookbook and modernised for today's kitchens. Where the book gave no heat or time, or said "a moderate oven", the temperatures and times here may be modern equivalents rather than the book's own figures.

Explore the science

The flavor team

The pairs that carry this dish. Each one is judged two ways: how much their aromas overlap, and how often cooks already put them together.

  1. Butter + creamtop 8% of all pairs
    Smell alikemoderate
    Cooked together41,516 recipes

    Shared aroma: delta-dodecalactone (sweet, creamy).

  2. Sugar + creamtop 9% of all pairs
    Smell alikemoderate
    Cooked together43,450 recipes

    Shared aroma: 2,3-butanedione (butter, sweet).

  3. Butter + flourtop 12% of all pairs
    Smell alikelow
    Cooked together124,287 recipes

    Shared aroma: isobutyraldehyde (malty, green).

  4. Flour + sugartop 15% of all pairs
    Smell alikemoderate
    Cooked together92,116 recipes

    Shared aroma: phenylacetaldehyde (hawthorne, honey).

  5. Onion + buttertop 15% of all pairs
    Smell alikemoderate
    Cooked together42,912 recipes

    Shared aroma: decanal (soap, orange peel).

Butter and flour barely smell alike, yet cooks put them together in 124,287 recipes: they work on texture and structure more than aroma.

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Onions
Browning and slow cooking give the soup its deep, sweet flavour.
Butter or dripping
Fat for frying the onions, carrying flavour and aiding browning.
Flour
Thickens the soup slightly as it cooks with the onions.
Egg yolks
Enrich the soup and thicken it gently with cream when stirred in off the heat.
Cream
Adds richness and smoothness, softening the soup's texture.

The step that matters

Quickly stir in the egg yolks and cream. Egg yolks thicken when heated, so if the soup is too hot or stirred slowly they can curdle into lumps. Stirring quickly distributes the yolks evenly and keeps the soup smooth.

Swap the onion

How well each one fits the dish's main ingredients (butter, flour, sugar, egg, cream):

  1. Leekfits better
  2. Chivefits better
  3. Arrowrootfits better
  4. Onionthe original

Fit is the average pairing score against butter, flour, sugar, egg, cream. Candidates are from the same food group and used in at least 100 recipes.

“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.

More onion soup recipes

French 31Brown 15with Milk 7White 5Bavarian 4Bermuda 4 See all 236 →

You might also like

Tomato SoupTomato Soup526 recipesBrown BreadBrown Bread461 recipesMutton BrothMutton Broth292 recipesYorkshire PuddingYorkshire Pudding264 recipes