Name: Cream of Tomato Soup
Ingredients: 1 quart canned tomato pulp or 1 small can of tomatoes; 1 slice onion; 2 tablespoons butter or drippings from 1 slice green pepper; Salt and pepper to taste; 2 tablespoons flour; A few grains of cayenne pepper; ¼ teaspoon bicarbonate of soda

Why it works: Tomato and pepper are a kitchen classic. They rank in the top 7% of all ingredient pairs, and 17,923 recipes mention both. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Cream of Tomato Soup

Ingredients

1 quart canned tomato pulp or 1 small can of tomatoes
1 slice onion
2 tablespoons butter or drippings from 1 slice green pepper
Salt and pepper to taste
2 tablespoons flour
A few grains of cayenne pepper
¼ teaspoon bicarbonate of soda

Directions

Combine tomatoes, onion, and green pepper in a saucepan and cook slowly for about 10 minutes.
Strain the mixture to remove solids.
In a separate bowl, rub together flour and butter or drippings until smooth.
Add the flour mixture to the milk and stir over medium heat until it thickens slightly.
Add bicarbonate of soda to the strained tomato juice.
Pour the milk mixture into the tomato juice just before serving.

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 + peppertop 7% of all pairs

Aroma overlapmoderate

Mentioned together17,923 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Tomato + oniontop 8% of all pairs

Aroma overlapmoderate

Mentioned together20,633 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + peppertop 11% of all pairs

Aroma overlapmoderate

Mentioned together68,474 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Butter + flourtop 12% of all pairs

Aroma overlaplow

Mentioned together124,287 recipes

Shared aroma: isobutyraldehyde (malty, green).
Onion + buttertop 15% of all pairs

Aroma overlapmoderate

Mentioned together42,912 recipes

Shared aroma: decanal (soap, orange peel).

Butter and flour share little aroma chemistry, yet 124,287 recipes mention both: they likely work on texture and structure more than aroma.

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, pepper, flour):

Capsicumbetter flavor fit
Okrabetter flavor fit
Eggplantbetter flavor fit
Onionthe original

Fit is the average pairing score against tomato, butter, pepper, flour. 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).