Name: Tomato Catsup Without Boiling
Ingredients: ½ peck ripe tomatoes, chopped fine; 1 quart vinegar; ½ cup brown sugar; ½ cup mustard seed; ½ cup coarse sea salt (formerly 'bay salt'); 1 tablespoon ground cloves; 1 tablespoon ground allspice; 1 tablespoon ground black pepper; 2 red peppers, chopped; 2 onions, chopped; 1 teaspoon celery seed

Why it works: Clove and allspice match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 7,874 recipes. Both carry estragole, which smells anise, licorice. The science ↓

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.

Clove + allspicetop 1% of all pairs

Smell alikestrong

Cooked together7,874 recipes

Shared aroma: estragole (anise, licorice).
Mustard + allspicetop 2% of all pairs

Smell alikestrong

Cooked together1,928 recipes

Shared aroma: methyleugenol (clove, spice).
Clove + peppertop 5% of all pairs

Smell alikestrong

Cooked together17,451 recipes

Shared aroma: ethyl octanoate (fruity, wine).
Allspice + peppertop 5% of all pairs

Smell alikestrong

Cooked together6,395 recipes

Shared aroma: estragole (anise, licorice).
Mustard + oniontop 6% of all pairs

Smell alikestrong

Cooked together9,259 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

Ripe tomatoes: Provides the bulk, body and sweet-tart base of the ketchup.
Vinegar: Adds acidity that sharpens flavor and helps preserve the ketchup.
Brown sugar: Adds sweetness and balances the acidity of the vinegar and tomatoes.
Coarse sea salt: Seasons the ketchup and draws out moisture from the vegetables.
Onions: Contribute savory depth and aroma as they soften into the mixture.
Red peppers: Add sweetness, color and a mild vegetal flavor.

The step that matters

Letting the mixture sit for several hours. Resting lets the salt, sugar, vinegar and spices slowly penetrate the chopped vegetables, so the flavors blend rather than tasting raw and separate.

Swap the tomato

How well each one fits the dish's main ingredients (vinegar, sugar, mustard, clove, allspice, pepper, onion):

Horseradishfits better
Shallotfits better
Capsicumfits better
Tomatothe original

Fit is the average pairing score against vinegar, sugar, mustard, clove, allspice, pepper, onion. 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.

Tomato Catsup Without Boiling