Why it works: Milk and vanilla are a kitchen classic. They rank in the top 5% of all ingredient pairs, and cooks put them together in 19,187 recipes. Both carry ethyl caproate, which smells fruity, apple peel. The science ↓
Boiled Custard
Ingredients
Directions
Beat the eggs slightly, then add the sugar and salt.
Mix the potato starch with a little milk, then add the remainder of the milk.
Cook the mixture in a double boiler for 5 minutes, or until it thickens.
Pour the thickened mixture gradually over the eggs, stirring constantly.
Cook in the double boiler for a few more minutes, watching carefully to prevent curdling.
Add the vanilla just before removing from heat.
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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Milk + vanillatop 5% of all pairsSmell alikemoderateCooked together19,187 recipes
Shared aroma: ethyl caproate (fruity, apple peel).
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Sugar + vanillatop 8% of all pairsSmell alikelowCooked together35,032 recipes
Shared aroma: beta-damascenone (apple, rose).
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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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Potato + vanillatop 16% of all pairsSmell alikemoderateCooked together383 recipes
Shared aroma: sotolon (curry, maple).
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Milk + eggtop 18% of all pairsSmell alikemoderateCooked together88,785 recipes
Shared aroma: 2-nonenal (fatty, green).
Sugar and vanilla barely smell alike, yet cooks put them together in 35,032 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
- Eggs
- Provide protein that sets and thickens the custard as it heats.
- Potato starch
- Thickens the milk into a smooth, creamy body as it cooks.
- Milk
- Forms the liquid base that the eggs and starch thicken.
- Sugar
- Adds sweetness and softens the set texture of the custard.
The step that matters
Cooking the eggs in the thickened mixture. Egg proteins set at a low temperature, so heating too fast or too long causes curdling. Gentle, constant stirring and a double boiler keep the custard smooth.
Swap the potato
How well each one fits the dish's main ingredients (sugar, milk, egg, vanilla):
- Sweet potatofits better
- Arrowrootfits better
- Capsicumfits better
- Potatothe original
Fit is the average pairing score against sugar, milk, egg, vanilla. 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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