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
Place the cheese in a chafing dish or double boiler.
Mix the mustard, salt, and cayenne; sprinkle over the cheese.
Add the butter in pieces and the milk.
When the cheese begins to melt, stir until completely melted.
Add the well-beaten egg; stir and cook for a moment longer.
Serve
Serve immediately on wafers or 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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Cheese + buttertop 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).
-
Cheese + mustardtop 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 give it body and its characteristic rich flavour.
- Egg
- Thickens the cheese mixture as it cooks, giving it a creamier, more set texture.
- Butter
- Adds fat that makes the melted cheese smooth and glossy rather than grainy.
- Milk
- Loosens the melting cheese into a pourable sauce with moisture.
- Mustard
- Adds sharpness that balances the richness of the cheese.
The step that matters
Adding the egg. Egg proteins set when heated, so the well-beaten egg must be stirred in over gentle heat and cooked only briefly. Too much heat or time can curdle or scramble it, leaving the sauce grainy instead of smooth.
Swap the mustard
How well each one fits the dish's main ingredients (cheese, pepper, butter, milk, egg):
- Potatofits better
- Capsicumfits better
- Asparagusfits better
- Mustardthe original
Fit is the average pairing score against cheese, pepper, butter, 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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