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 ↓
White Sauce
Ingredients
Directions
Make the roux
In a bowl, knead the butter and flour together until smooth.
Melt the mixture in a saucepan over low heat with the milk.
Finish the sauce
In a separate bowl, beat the egg yolk with the milk or cream.
Stir the egg mixture into the butter mixture.
Cook over low heat, stirring constantly until thickened.
Add chopped parsley if desired.
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 + parsleytop 12% of all pairsSmell alikemoderateCooked together16,675 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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Butter + parsleytop 15% of all pairsSmell alikemoderateCooked together28,563 recipes
Shared aroma: trans-2-hexenal (green, leafy).
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
- Butter
- Adds fat and richness, and helps give the sauce a smooth, silky mouthfeel.
- Flour
- Starch thickens the liquid as it heats, giving the sauce body.
- Milk
- Forms the liquid base of the sauce that the starch thickens.
- Egg yolk
- Adds richness and, when gently heated, helps thicken and enrich the sauce.
The step that matters
Cook over low heat, stirring constantly until thickened. Starch gelatinizes as the sauce heats, so it thickens best over gentle heat with constant stirring. Too much heat or too little stirring can cause lumps or scorch the bottom. Egg yolk can curdle if it gets too hot, so keep the heat low.
Swap the parsley
The recipe marks parsley as optional. How well each one fits the dish's main ingredients (butter, flour, milk, egg):
- Nutmegfits better
- Cinnamonfits better
- Capersfits about as well
- Parsleythe original
Fit is the average pairing score against butter, flour, milk, egg. 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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