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
Cook the onions
Chop the onions.
In a small saucepan, melt the butter and add the onions.
Stew the onions gradually until done.
Finish the soup
Add the stewed onions to the good stock.
Season with salt, pepper, and cayenne if needed.
Strain the soup and stir in the boiling cream.
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.
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Butter + creamtop 8% of all pairsSmell alikemoderateCooked together41,516 recipes
Shared aroma: delta-dodecalactone (sweet, creamy).
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Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Onion + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
-
Onion + creamtop 18% of all pairsSmell alikelowCooked together10,827 recipes
Shared aroma: 2-nonanone (fruity, floral).
-
Butter + peppertop 21% of all pairsSmell alikemoderateCooked together85,593 recipes
Shared aroma: trans-2-nonenal (cardboard, fatty).
Onion and cream barely smell alike, yet cooks put them together in 10,827 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
- Soften as they stew, releasing sweetness that forms the soup's main flavor base.
- Butter
- Fat that cooks the onions gently and carries flavor through the soup.
- Stock
- Provides the liquid base and savory flavor of the soup.
- Cream
- Adds richness and a smooth, mellow texture to the finished soup.
The step that matters
Stew the onions gradually until done. Slow, gentle heat softens the onions and draws out their natural sugars without scorching them. Fast, high heat browns and burns the onions, giving the soup a bitter taste and uneven texture.
Swap the onion
How well each one fits the dish's main ingredients (butter, pepper, cream):
- Potatofits better
- Spinachfits about as well
- Capsicumfits about as well
- Onionthe original
Fit is the average pairing score against butter, pepper, 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.
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