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 ↓
Welsh Rarebit
Ingredients
Directions
Make the rarebit
Melt the butter in a double boiler.
Add salt, mustard, and pepper.
Stir in the cheese and melt it.
Once melted, add the milk and beaten egg.
Stir constantly until the mixture thickens and is smooth.
Serve
Serve immediately on crisp wafers or dry toast.
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 + cheesetop 8% of all pairsSmell alikemoderateCooked together7,962 recipes
Shared aroma: delta-dodecalactone (sweet, creamy).
-
Mustard + peppertop 9% of all pairsSmell alikemoderateCooked together15,430 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Cheese + milktop 10% of all pairsSmell alikemoderateCooked together4,426 recipes
Shared aroma: delta-dodecalactone (sweet, creamy).
-
Mustard + cheesetop 11% of all pairsSmell alikemoderateCooked together1,805 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
- Cheese
- Melts into the sauce to provide the main body and rich flavor.
- Egg
- Thickens the sauce as it heats and helps it set smooth and creamy.
- Butter
- Adds fat that carries flavor and keeps the melted cheese sauce smooth.
- Milk
- Loosens the cheese into a pourable sauce and adds moisture.
- Mustard
- Adds sharp, tangy flavor that cuts the richness of the cheese.
The step that matters
Stir constantly until the mixture thickens and is smooth. The egg proteins set with gentle heat and can curdle or scramble if the mixture overheats or sits still, so constant stirring over a double boiler keeps the sauce smooth.
Swap the mustard
How well each one fits the dish's main ingredients (butter, pepper, cheese, milk, egg):
- Potatofits better
- Capsicumfits better
- Asparagusfits better
- Mustardthe original
Fit is the average pairing score against butter, pepper, cheese, 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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