Name: Tomato Catsup
Ingredients: 1 peck ripe tomatoes; 1 cup sugar; ½ cup coarse sea salt; 1 quart good cider vinegar; spices to taste

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 ↓

Tomato Catsup

Ingredients

Directions

Prepare

Wash and chop the ripe tomatoes.

Make the ketchup

In a large pot, combine the tomatoes, sugar, coarse sea salt, and cider vinegar.
Cook the mixture over medium heat until well combined and thickened.
Add spices to taste and stir well.

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).
Sugar + vinegartop 15% of all pairs

Smell alikemoderate

Cooked together20,806 recipes

Shared aroma: beta-damascenone (apple, rose).
Tomato + vinegartop 16% of all pairs

Smell alikemoderate

Cooked together5,063 recipes

Shared aroma: beta-damascenone (apple, rose).
Tomato + cidertop 19% of all pairs

Smell alikemoderate

Cooked together524 recipes

Shared aroma: 1-octen-3-one (mushroom, metallic).
Sugar + cidertop 27% of all pairs

Smell alikelow

Cooked together3,308 recipes

Shared aroma: ethanol (alcoholic, ethereal).

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

What each ingredient does

Ripe tomatoes: Provide the main body and flavor base of the ketchup.
Sugar: Adds sweetness and balances the acidity of the vinegar.
Cider vinegar: Adds acidity that gives ketchup its tang and helps preserve it.