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 ↓
Potato Au Gratin
Ingredients
Directions
The book gives no oven temperature. The 350°F (175°C) in the steps was added when the recipe was transcribed, as a starting point.
Prepare the white sauce
To make the white sauce, heat the butter in a saucepan.
Stir in the flour and salt, then gradually add the hot milk.
Cook thoroughly, stirring until smooth before pouring over the potatoes.
Assemble and bake
Preheat the oven to 350°F (175°C).
Arrange the sliced or diced potatoes in layers in a baking dish.
Sprinkle each layer with cheese, or substitute with a dredging of flour and small bits of butter.
Pour the white sauce over the potatoes, adding the buttered cracker crumbs last.
Bake for 30 minutes.
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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Cheese + buttertop 8% of all pairsSmell alikemoderateCooked together7,962 recipes
Shared aroma: delta-dodecalactone (sweet, creamy).
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Potato + milktop 9% of all pairsSmell alikemoderateCooked together3,611 recipes
Shared aroma: (e,z)-2,6-nonadienal (cucumber, melon).
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Cheese + milktop 10% of all pairsSmell alikemoderateCooked together4,426 recipes
Shared aroma: delta-dodecalactone (sweet, creamy).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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
- Potatoes
- Form the bulk of the dish, cooking into tender layers that hold the sauce.
- White sauce
- Supplies moisture and richness that cook into the potatoes as they bake.
- Cheese
- Melts into the layers and adds savory flavor and a golden surface.
- Flour
- Thickens the butter and milk into a smooth sauce that clings to the potatoes.
- Buttered cracker crumbs
- Toast on top in the oven, adding a crisp, browned topping.
The step that matters
Cook the white sauce until smooth. Flour must be cooked with the butter and stirred while the hot milk is added, so it thickens evenly without lumps or a raw starchy taste.
Swap the potato
How well each one fits the dish's main ingredients (sauce, cheese, butter, flour, milk):
- Potatothe original
- Mustardfits about as well
- Shallotfits about as well
- Capsicumfits about as well
Fit is the average pairing score against sauce, cheese, butter, flour, 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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