Why it works: Onion and carrot are a kitchen classic. They rank in the top 6% of all ingredient pairs, and cooks put them together in 21,601 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Pea Soup
Ingredients
Directions
Prepare
Soak the split peas in cold water overnight.
Cook the soup
In a pot, combine the soaked peas, ham or bones, and enough water to cover.
Boil slowly for 3 hours, adding minced onions and grated carrots.
Add the spice bag and continue to simmer.
If the soup is not thick enough, stir in the flour.
Remove the bones and season with salt.
Serve
Cut the toasted bread into dice and add to the soup before serving.
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.
Photo for illustrative purposes only · Contact us to use it
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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Onion + carrottop 6% of all pairsSmell alikemoderateCooked together21,601 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Ham + breadtop 7% of all pairsSmell alikemoderateCooked together2,536 recipes
Shared aroma: 2-acetyl-1-pyrroline (popcorn, roasted).
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Peas + carrottop 7% of all pairsSmell alikemoderateCooked together2,994 recipes
Shared aroma: 2-isobutyl-3-methoxypyrazine (green bell pepper, earthy).
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Peas + breadtop 11% of all pairsSmell alikemoderateCooked together804 recipes
Shared aroma: hexyl acetate (fruity, apple).
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Peas + oniontop 13% of all pairsSmell alikemoderateCooked together5,460 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Split peas
- Break down during long simmering to thicken the soup and give it body.
- Onions
- Melt into the broth as they cook, adding sweetness and savory depth.
- Carrots
- Soften during simmering, adding sweetness and body to the soup.
- Common flour
- Thickens the soup when stirred in, adding body to a thin broth.
The step that matters
Simmering the soup slowly. Split peas need a long, gentle simmer to soften fully and release starch that thickens the soup. Boiling hard can break the liquid unevenly and leave peas firm or the soup scorched on the bottom, so keep it at a slow simmer and stir occasionally.
Swap the onion
How well each one fits the dish's main ingredients (peas, ham, carrot, flour, bread):
- Leekfits better
- Shallotfits better
- Turnipfits better
- Onionthe original
Fit is the average pairing score against peas, ham, carrot, flour, bread. 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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