Why it works: Tomato and pepper are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 17,923 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Tomato Relish
Ingredients
Directions
Combine tomatoes, onions, and peppers in a large pot.
Add vinegar, sugar, and salt.
Boil gently for 1 hour, stirring occasionally.
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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Tomato + peppertop 7% of all pairsSmell alikemoderateCooked together17,923 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Tomato + oniontop 8% of all pairsSmell alikemoderateCooked together20,633 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Onion + vinegartop 14% of all pairsSmell alikemoderateCooked together18,226 recipes
Shared aroma: acetic acid (sour, vinegar).
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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 and moisture that cook down into the relish body.
- Onions
- Add savory depth and aromatic sweetness as they soften during cooking.
- Peppers
- Contribute mild bitterness, crunch-softening texture, and fresh vegetable flavor.
- Vinegar
- Adds acidity that brightens flavor and helps preserve the relish.
- Sugar
- Balances the acidity of the vinegar and rounds out the flavor.
The step that matters
Boil gently for 1 hour, stirring occasionally. A gentle boil lets the mixture thicken slowly while the vegetables soften evenly. Stirring prevents scorching on the bottom of the pot, which would taste burnt and harsh.
Swap the onion
How well each one fits the dish's main ingredients (tomato, pepper, vinegar, sugar):
- Capsicumfits better
- Cucumberfits better
- Mustardfits better
- Onionthe original
Fit is the average pairing score against tomato, pepper, vinegar, sugar. 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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