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 Ketchup
Ingredients
Directions
Prepare the tomatoes
Select red-ripe tomatoes, discarding any green or yellowish parts.
Chop the sweet red pepper and onions.
Add the chopped sweet red pepper and onions to the tomatoes.
Cook the tomatoes thoroughly.
Strain the cooked tomatoes through a colander or sieve, saving all pulp.
Make the ketchup
For every gallon of pulp, add salt, sugar, mustard powder, vinegar, allspice, cloves, cinnamon, black pepper, and sliced red peppers.
Cook the mixture for 1.5 hours until nearly thick.
Add vinegar and cook until thick.
Bottle and process
Pour the ketchup into hot sterilized bottles.
Process the hot bottles in boiling water for 30 minutes.
Seal the bottles tightly.
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).
-
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
- Red-ripe tomatoes
- Provide the main body, flavour and liquid that cooks down into the ketchup.
- Onions
- Add savoury depth and aroma as they soften during cooking.
- Sweet red pepper
- Adds mild sweetness and colour to the base.
- Vinegar
- Adds acidity that gives the ketchup its tang and helps preserve it.
- Sugar
- Adds sweetness that balances the acidity and tomato flavour.
- Whole cloves
- Contribute warm, aromatic spice flavour during the long simmer.
The step that matters
Cook the mixture until nearly thick. Tomato pulp thickens as water evaporates during long simmering. Stopping too early leaves the ketchup thin, while over-reducing makes it stiff and can scorch on the bottom of the pot.
Swap the tomato
How well each one fits the dish's main ingredients (pepper, onion, sugar, mustard, vinegar, allspice, clove):
- Horseradishfits better
- Shallotfits better
- Capsicumfits better
- Tomatothe original
Fit is the average pairing score against pepper, onion, sugar, mustard, vinegar, allspice, clove. 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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