Why it works: Milk and butter are a kitchen classic. They rank in the top 7% of all ingredient pairs, and 81,283 recipes mention both. Both carry (z)-4-heptenal, which smells biscuit, cream. The science ↓
Cream of Tomato Soup
Ingredients
Directions
Prepare the base
Heat the milk in a double boiler.
Mix the flour and butter together.
Add the flour and butter mixture to the milk.
Prepare the tomatoes
Cook the tomatoes for twenty minutes.
Strain the tomatoes.
Add the baking soda, sugar, salt, and pepper to the strained tomatoes.
Combine and serve
Combine the tomato mixture with the milk.
Serve immediately.
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.
-
Milk + buttertop 7% of all pairsAroma overlapmoderateMentioned together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
-
Tomato + peppertop 7% of all pairsAroma overlapmoderateMentioned together17,923 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Butter + flourtop 12% of all pairsAroma overlaplowMentioned together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Milk + flourtop 14% of all pairsAroma overlaplowMentioned together78,219 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Flour + sugartop 15% of all pairsAroma overlapmoderateMentioned together92,116 recipes
Shared aroma: phenylacetaldehyde (hawthorne, honey).
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
What each ingredient does
- Milk
- Forms the creamy liquid base of the soup.
- Butter
- Adds fat and richness, and helps the flour blend smoothly.
- Flour
- Thickens the milk so the soup becomes smooth and body-rich.
- Tomatoes
- Provide the main tomato flavor and acidity.
- Baking soda
- Neutralizes some tomato acidity, reducing the risk of curdling the milk.
The step that matters
Combine the tomato mixture with the milk. Acidic tomatoes can curdle hot milk. Keeping the milk warm rather than boiling and combining gently helps the soup stay smooth.
“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.
You might also like
The Sunday pairing: one pairing, the chemistry behind it, and how to cook it. No spam, unsubscribe anytime.
Prefer an account? Create a free account for sign-in; Pro adds the full results and chemistry.

Tomato Soup526 recipes
Tomato Bisque61 recipes
Cream Tomato Soup28 recipes
Tomato Fritters23 recipes