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 ↓
Common Catsup
Ingredients
Directions
Prepare the tomato juice
Cook the chopped tomatoes thoroughly, skins included.
Once cool, strain the mixture through a sieve to extract the juice.
Make the ketchup
In a large pot, combine the tomato juice, salt, pepper, cinnamon, and cider vinegar.
Cook the mixture over medium heat until it thickens.
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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Cider + vinegartop 6% of all pairsSmell alikemoderateCooked together3,431 recipes
Shared aroma: 4-ethyl-2-methoxyphenol (smoky, clove).
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Tomato + peppertop 7% of all pairsSmell alikemoderateCooked together17,923 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Pepper + cinnamontop 9% of all pairsSmell alikestrongCooked together4,890 recipes
Shared aroma: methyl cinnamate (strawberry).
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Tomato + cinnamontop 11% of all pairsSmell alikemoderateCooked together1,348 recipes
Shared aroma: beta-phellandrene (minty, terpene).
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Pepper + vinegartop 14% of all pairsSmell alikemoderateCooked 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 bulk, pulp and natural sugars that become the ketchup's body and flavour.
- Cider vinegar
- Adds acidity that brightens the flavour and helps preserve the finished ketchup.
- Black pepper
- Adds a mild, sharp heat that rounds out the tomato flavour.
- Ground cinnamon
- Adds warm, aromatic spice notes that complement the tomatoes and vinegar.
The step that matters
Cooking the mixture until it thickens. Water evaporates slowly as the tomato juice simmers, concentrating sugars and pulp. Stopping too early leaves a thin sauce, while cooking too long over heat can scorch the bottom of the pot.
Swap the cinnamon
How well each one fits the dish's main ingredients (tomato, pepper, cider, vinegar):
- Thymefits better
- Tarragonfits better
- Basilfits better
- Cinnamonthe original
Fit is the average pairing score against tomato, pepper, cider, 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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