Skip to main content
Main

Onion Soup

A creamy onion soup made with onions, butter, flour, milk, water, potato, sweet cream, seasoned with salt and pepper.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 8 ingredients
Jump to recipe ↓

Why it works: Onion and potato are a kitchen classic. They rank in the top 3% of all ingredient pairs, and cooks put them together in 9,023 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Onion Soup

Ingredients

Directions

Make the base

  1. Slice the onions and fry them in butter until brown.

  2. Stir in the flour.

Make the soup

  1. In a saucepan, slowly add the milk and water (about one-third water).

  2. Season with salt and pepper.

  3. Add the grated potato and cook in boiling water for 10 minutes.

  4. Stir in the sweet cream and serve immediately.

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. Onion + potatotop 3% of all pairs
    Smell alikemoderate
    Cooked together9,023 recipes

    Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

  2. Butter + milktop 7% of all pairs
    Smell alikemoderate
    Cooked together81,283 recipes

    Shared aroma: (z)-4-heptenal (biscuit, cream).

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

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

  4. Pepper + potatotop 9% of all pairs
    Smell alikemoderate
    Cooked together8,305 recipes

    Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

  5. Milk + potatotop 9% of all pairs
    Smell alikemoderate
    Cooked together3,611 recipes

    Shared aroma: (e,z)-2,6-nonadienal (cucumber, melon).

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

What each ingredient does

Onions
Browned in butter, they build the savoury, sweet flavour base of the soup.
Butter
Fat that carries the onion flavour and helps the onions brown.
Flour
Stirred into the browned onions, it thickens the milk and water into a smooth body.
Milk
Forms the creamy liquid base of the soup.
Grated potato
Cooks down to add body and extra thickness to the soup.
Sweet cream
Stirred in at the end, it adds richness and a silky finish.

The step that matters

Slowly adding the milk and water to the flour-onion mixture. Adding liquid gradually while stirring lets the flour disperse evenly, preventing lumps. Dumping it in at once makes flour clump, leaving a grainy, uneven texture.

Swap the onion

How well each one fits the dish's main ingredients (butter, flour, milk, pepper, potato, cream):

  1. Chivefits about as well
  2. Leekfits about as well
  3. Spinachfits about as well
  4. Onionthe original

Fit is the average pairing score against butter, flour, milk, pepper, potato, 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

Potato CroquettesPotato Croquettes255 recipesPotato RollsPotato Rolls78 recipesPotato ChipsPotato Chips53 recipesSweet Potato CroquettesSweet Potato Croquettes53 recipes