Name: Tomato Catsup
Ingredients: tomatoes; coarse sea salt; black pepper; whole peppercorns; mace; cloves; vinegar

Why it works: Pepper and clove match in chemistry and in kitchens. They rank in the top 5% of all ingredient pairs, and cooks put them together in 17,451 recipes. Both carry ethyl octanoate, which smells fruity, wine. The science ↓

Tomato Catsup

Ingredients

Directions

Prepare the tomato juice

Gather the tomatoes and place them in a skillet covered tightly until the juice is drawn out.
Wring the tomatoes through a coarse cloth to extract the juice.
Season the juice with black pepper and coarse sea salt.

Cook and finish

Boil the mixture without skimming, adding whole peppercorns, mace, and cloves.
Once cooled, add one third of good vinegar.
Bottle and cork the catsup well, and store in a cool place.

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.

Pepper + clovetop 5% of all pairs

Smell alikestrong

Cooked together17,451 recipes

Shared aroma: ethyl octanoate (fruity, wine).
Mace + clovetop 6% of all pairs

Smell alikelow

Cooked together8,400 recipes

Shared aroma: methyleugenol (clove, spice).
Tomato + peppertop 7% of all pairs

Smell alikemoderate

Cooked together17,923 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Tomato + clovetop 12% of all pairs

Smell alikemoderate

Cooked together3,474 recipes

Shared aroma: ethyl caproate (fruity, apple peel).
Pepper + vinegartop 14% of all pairs

Smell alikemoderate

Cooked together27,814 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).

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

What each ingredient does

Tomatoes: Provide the main body and flavor of the ketchup once their juice is extracted and reduced.
Vinegar: Adds acidity that sharpens the flavor and helps keep the finished ketchup stable.
Coarse sea salt: Seasons the juice and brings out the savory flavor of the tomatoes.