Name: Tomato Soup
Ingredients: 2 pounds tomatoes; 2 ounces butter; 1 onion, finely chopped

Why it works: Tomato and onion are a kitchen classic. They rank in the top 8% of all ingredient pairs, and 20,633 recipes mention both. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Tomato Soup

Ingredients

2 pounds tomatoes
2 ounces butter
1 onion, finely chopped

Directions

Remove the stalks from the tomatoes and wipe them clean.
Boil a large bowl of water and drop in four tomatoes at a time for 20 seconds.
Quickly remove the tomatoes and peel off the skins.
Cut the tomatoes in half and remove the seeds.
In a stewpan, melt the butter with the chopped onion over medium heat for 3 minutes.

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.

Photo for illustrative purposes only · Contact us to use it

Explore the science

The flavor team

The pairs that carry this dish. Each one is judged two ways: how much aroma chemistry they share, and how many recipes mention both.

Tomato + oniontop 8% of all pairs

Aroma overlapmoderate

Mentioned together20,633 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Butter + oniontop 15% of all pairs

Aroma overlapmoderate

Mentioned together42,912 recipes

Shared aroma: decanal (soap, orange peel).
Tomato + buttertop 22% of all pairs

Aroma overlapmoderate

Mentioned together6,918 recipes

Shared aroma: 3-hexenal (apple, fruity).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

Flavor stand-ins for the onion

How well each one fits the dish's main ingredients (tomato, butter):

Capsicumbetter flavor fit
Potatobetter flavor fit
Okraabout as good a flavor fit
Onionthe original

Fit is the average pairing score against tomato, butter. Candidates are from the same food group and used in at least 100 recipes. This compares flavor only: it does not check the job the ingredient does in the dish (bulk, moisture, acidity, structure).