Why it works: Allspice and clove 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 ↓
Tomato Catsup
Ingredients
Directions
Prepare the tomatoes
Cut the tomatoes into quarters, removing the stem and green parts.
Stew the tomatoes and onions slowly until soft but not disintegrated.
Strain the mixture through a sieve or fruit strainer.
Season and thicken
Add salt, black pepper, mustard powder, allspice, cloves, and red pepper to the liquid.
Boil the mixture slowly for 1 hour until it thickens.
Stir in the vinegar and pour the catsup into pint ale bottles.
Bottle and store
Seal the bottles with wax and store in a cool place.
Shake before decanting into a cruet. It improves with age, especially after the third year.
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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Allspice + clovetop 1% of all pairsSmell alikestrongCooked together7,874 recipes
Shared aroma: estragole (anise, licorice).
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Mustard + allspicetop 2% of all pairsSmell alikestrongCooked together1,928 recipes
Shared aroma: methyleugenol (clove, spice).
-
Pepper + clovetop 5% of all pairsSmell alikestrongCooked together17,451 recipes
Shared aroma: ethyl octanoate (fruity, wine).
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Pepper + allspicetop 5% of all pairsSmell alikestrongCooked together6,395 recipes
Shared aroma: estragole (anise, licorice).
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Onion + mustardtop 6% of all pairsSmell alikestrongCooked 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
- Provide the main body, moisture and tomato flavour of the ketchup.
- Onions
- Add savoury sweetness and aroma, and help give body as they soften.
- Vinegar
- Adds acidity that sharpens flavour and helps preserve the finished ketchup.
- Coarse sea salt
- Seasons the sauce and draws out flavour from the tomatoes and onions.
- Mustard powder
- Adds pungent, sharp flavour that balances the sweetness of the tomatoes.
The step that matters
Boil slowly after straining. Slow boiling reduces water and concentrates the tomato solids, so the sauce thickens. Fast boiling can scorch the sugars on the bottom of the pan and give a burnt taste.
Swap the tomato
How well each one fits the dish's main ingredients (onion, pepper, mustard, allspice, clove, vinegar):
- Horseradishfits better
- Shallotfits better
- Capsicumfits better
- Tomatothe original
Fit is the average pairing score against onion, pepper, mustard, allspice, clove, vinegar. 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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