Why it works: Butter and milk are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 81,283 recipes. Both carry (z)-4-heptenal, which smells biscuit, cream. The science ↓
Split Pea Soup
Ingredients
Directions
Prepare the peas
Wash the peas well and soak them in cold water for 24 hours (or 1 night at lower altitudes).
Drain the soaked peas.
Place the drained peas in a pot with fresh cold water.
Bring the pot to a boil and cook until the peas are soft, adding water as needed.
Mash the soft peas through a strainer.
Make the cream sauce
Melt the butter in a separate pan.
Stir the flour, salt, and pepper into the melted butter.
Gradually add the milk to the butter mixture until it becomes thick and creamy.
Combine and serve
Combine the strained peas with the creamed milk mixture.
Cook the combined mixture together for 10 minutes.
Serve the soup with fried diced bread.
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 + milktop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Flour + milktop 14% of all pairsSmell alikelowCooked together78,219 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Peas + peppertop 15% of all pairsSmell alikemoderateCooked together5,331 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Peas + milktop 16% of all pairsSmell alikemoderateCooked together1,309 recipes
Shared aroma: hexanal (green, grassy).
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
- Split peas
- Break down during cooking to give the soup its body and thick texture.
- Butter
- Carries fat that enriches the flavour and helps form the base of the cream sauce.
- Flour
- Thickens the butter and milk mixture so it becomes smooth and creamy.
- Milk
- Adds creaminess and softness to the sauce, rounding out the soup.
The step that matters
Gradually add the milk to the butter mixture. Adding milk slowly while stirring lets the flour starch hydrate evenly, which prevents lumps and gives a smooth, thick sauce.
Swap the peas
How well each one fits the dish's main ingredients (butter, flour, pepper, milk):
- Almondfits better
- Chestnutfits better
- Milletfits better
- Peasthe original
Fit is the average pairing score against butter, flour, pepper, milk. 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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