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Sauce

Tomato Ketchup

A thick tomato sauce made with tomatoes, mustard, pepper, salt, ginger, sugar, and vinegar.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 8 ingredients
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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 Ketchup

Ingredients

Directions

  1. Combine all ingredients in a large pot.

  2. Boil slowly, stirring occasionally, until thickened.

  3. Pour into bottles while hot, then seal the bottles and store in a cool place.

Recipe from a historical cookbook (Internet Archive).

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.

  1. Tomato + peppertop 7% of all pairs
    Smell alikemoderate
    Cooked together17,923 recipes

    Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

  2. Mustard + vinegartop 7% of all pairs
    Smell alikemoderate
    Cooked together14,067 recipes

    Shared aroma: isobutyraldehyde (malty, green).

  3. Pepper + gingertop 9% of all pairs
    Smell alikestrong
    Cooked together6,800 recipes

    Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

  4. Mustard + peppertop 9% of all pairs
    Smell alikemoderate
    Cooked together15,430 recipes

    Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

  5. Mustard + gingertop 10% of all pairs
    Smell alikemoderate
    Cooked together2,456 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

Strained tomatoes
Provide the main body, moisture and tomato flavour of the ketchup.
Vinegar
Adds acidity that sharpens the flavour and helps preserve the ketchup.
Brown sugar
Adds sweetness that balances the acidity and tang of the vinegar.
Mustard
Contributes sharp, pungent flavour that gives the ketchup its savoury bite.

The step that matters

Boil slowly and stir occasionally until thickened. Slow simmering lets water evaporate gradually so the tomato mixture thickens evenly. Stirring prevents scorching on the bottom of the pot, which would add a burnt taste.

Swap the tomato

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

  1. Horseradishfits better
  2. Capsicumfits better
  3. Radishfits better
  4. Tomatothe original

Fit is the average pairing score against mustard, pepper, ginger, sugar, 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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