Name: Green Tomatoes Made in Mustard
Ingredients: 1 peck green tomatoes; 6 onions; 2 green or red peppers; 2 pounds brown sugar; 2 quarts cider vinegar; 1 pound mustard

Why it works: Onion and mustard match in chemistry and in kitchens. They rank in the top 6% of all ingredient pairs, and cooks put them together in 9,259 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Green Tomatoes Made in Mustard

Ingredients

Directions

Make the syrup

Boil mustard, brown sugar, and cider vinegar together until it forms a thick syrup.

Assemble and cook

Layer the green tomatoes and onions alternately in a pot until all are used.
Boil the mixture until the tomatoes are tender.

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.

Onion + mustardtop 6% of all pairs

Smell alikestrong

Cooked together9,259 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Cider + vinegartop 6% of all pairs

Smell alikemoderate

Cooked together3,431 recipes

Shared aroma: 4-ethyl-2-methoxyphenol (smoky, clove).
Tomato + peppertop 7% of all pairs

Smell alikemoderate

Cooked together17,923 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Vinegar + mustardtop 7% of all pairs

Smell alikemoderate

Cooked together14,067 recipes

Shared aroma: isobutyraldehyde (malty, green).
Tomato + oniontop 8% of all pairs

Smell alikemoderate

Cooked together20,633 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

Green tomatoes: Form the bulk of the dish and soften into tender pieces during boiling.
Onions: Add savory flavor and soften into the sweet-tart mixture as it cooks.
Brown sugar: Adds sweetness and helps thicken the vinegar into a syrup.
Cider vinegar: Provides acidity that balances the sweetness and sharpens the flavor.
Mustard: Contributes sharp, pungent flavor that defines the dish.

The step that matters

Boil until the tomatoes are tender. Green tomatoes are firm and starchy, so they need enough sustained boiling in the acidic syrup to soften fully. Stopping early leaves them hard, while overcooking can break them down into a mush.

Swap the onion

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

Capsicumfits better
Cucumberfits better
Horseradishfits better
Onionthe original

Fit is the average pairing score against tomato, pepper, sugar, cider, vinegar, mustard. 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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Green Tomatoes Made in Mustard