Why it works: Allspice and mustard match in chemistry and in kitchens. They rank in the top 2% of all ingredient pairs, and cooks put them together in 1,928 recipes. Both carry methyleugenol, which smells clove, spice. The science ↓
Tomato Catsup
2 quartsIngredients
Directions
Bruise the tomatoes, salt, black pepper, allspice, red pepper pods, and mustard seed finely.
Simmer the mixture slowly in 1 pint of vinegar for 3 hours.
Strain the mixture and boil it down to 2 quarts.
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.
-
Allspice + mustardtop 2% of all pairsSmell alikestrongCooked together1,928 recipes
Shared aroma: methyleugenol (clove, spice).
-
Pepper + allspicetop 5% of all pairsSmell alikestrongCooked together6,395 recipes
Shared aroma: estragole (anise, licorice).
-
Tomato + peppertop 7% of all pairsSmell alikemoderateCooked together17,923 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Mustard + vinegartop 7% of all pairsSmell alikemoderateCooked together14,067 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Pepper + mustardtop 9% of all pairsSmell alikemoderateCooked together15,430 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
- Tomatoes
- Form the main body of the sauce and break down into a thick, sweet base as they cook.
- Vinegar
- Adds sharp acidity that gives the ketchup its tang and helps preserve it.
- Allspice
- Contributes warm, aromatic spice notes that round out the tomato flavour.
- Red pepper pods
- Add gentle heat that builds as the sauce simmers and reduces.
- Mustard seed
- Adds a pungent, slightly bitter note that softens during long simmering.
The step that matters
Simmer slowly and reduce to 2 quarts. A long, slow simmer breaks down the tomato solids and drives off water, which thickens the sauce and concentrates its flavour. Too much heat can scorch the sugars in the tomatoes and leave a burnt taste.
Swap the tomato
How well each one fits the dish's main ingredients (pepper, allspice, mustard, vinegar):
- Horseradishfits better
- Radishfits better
- Shallotfits better
- Tomatothe original
Fit is the average pairing score against pepper, allspice, mustard, 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.
More ketchup recipes
You might also like
Tomato Soup526 recipes
Cream of Tomato Soup107 recipes
Tomato Bisque61 recipes
Cream Tomato Soup28 recipesThe free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.