Name: Welsh Rarebit Sandwiches
Ingredients: 8 ounces mild cheese; 2 ounces butter; 1 teaspoon mustard; 2 tablespoons cider vinegar; slices of bread

Why it works: Cider and vinegar are a kitchen classic. They rank in the top 6% of all ingredient pairs, and cooks put them together in 3,431 recipes. Both carry 4-ethyl-2-methoxyphenol, which smells smoky, clove. The science ↓

Welsh Rarebit Sandwiches

Ingredients

Directions

Combine the cheese, butter, and mustard in a mortar.
Pound the mixture well and dilute it with cider vinegar.
Spread the cheese mixture between slices of bread.

Recipe from a historical cookbook (Internet Archive).

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.

Cider + vinegartop 6% of all pairs

Smell alikemoderate

Cooked together3,431 recipes

Shared aroma: 4-ethyl-2-methoxyphenol (smoky, clove).
Butter + breadtop 7% of all pairs

Smell alikemoderate

Cooked together27,232 recipes

Shared aroma: delta-decalactone (sweet, creamy).
Cheese + breadtop 7% of all pairs

Smell alikemoderate

Cooked together2,130 recipes

Shared aroma: delta-decalactone (sweet, creamy).
Mustard + vinegartop 7% of all pairs

Smell alikemoderate

Cooked together14,067 recipes

Shared aroma: isobutyraldehyde (malty, green).
Cheese + buttertop 8% of all pairs

Smell alikemoderate

Cooked together7,962 recipes

Shared aroma: delta-dodecalactone (sweet, creamy).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Mild cheese: Supplies most of the rich, savoury flavour and fat that gives the spread its body.
Butter: Adds fat that makes the cheese paste smooth and easy to spread.
Mustard: Adds sharp, pungent flavour that cuts through the richness of the cheese.
Cider vinegar: Adds acidity and thins the paste, giving it a brighter taste and looser texture.

The step that matters

Pound the mixture well. Thorough pounding breaks down the cheese and blends it evenly with the butter, so the paste becomes smooth rather than lumpy. Adding the vinegar gradually while pounding helps the mixture emulsify and stay spreadable.

“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.

Brown Bread461 recipes

Macaroni and Cheese102 recipes

White Bread80 recipes

Bread Omelette60 recipes

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Welsh Rarebit Sandwiches