Name: Cucumber Soup
Ingredients: 8 to 20 cucumbers; 2 mild onions (white part only); ½ cup veal stock (or more as needed); ½ to 1 pint boiling cream; Salt to taste; Cayenne pepper to taste; Yolks of 6 to 8 eggs (optional); 2 teaspoons chili vinegar (optional); 3 teaspoons minced parsley (optional)

Why it works: Pepper and parsley match in chemistry and in kitchens. They rank in the top 2% of all ingredient pairs, and cooks put them together in 34,122 recipes. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓

Cucumber Soup

Ingredients

8 to 20 cucumbers
2 mild onions (white part only)
½ cup veal stock (or more as needed)
½ to 1 pint boiling cream
Salt to taste
Cayenne pepper to taste
Yolks of 6 to 8 eggs (optional)
2 teaspoons chili vinegar (optional)
3 teaspoons minced parsley (optional)

Directions

Prepare the cucumbers

Pare the cucumbers, split them, and remove the seeds.
Sprinkle a little salt over the cucumbers and let them drain for 1 hour.

Make the soup

In a saucepan, combine the cucumbers and the white part of the onions.
Cover the mixture with veal stock.
Stew gently for 45 to 75 minutes until the vegetables are tender.
Press the mixture through a fine sieve.
Add more stock to reach the desired soup quantity.
Stir in arrowroot, rice flour, or a similar thickener to achieve a good consistency.
Add boiling cream.
Season with salt and cayenne pepper.

Finish and serve

(Optional) Mix egg yolks with chili vinegar, then stir the egg mixture into the soup.
(Optional) Add minced parsley 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.

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.

Pepper + parsleytop 2% of all pairs

Smell alikestrong

Cooked together34,122 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Cucumber + parsleytop 7% of all pairs

Smell alikestrong

Cooked together1,564 recipes

Shared aroma: trans-2-hexenal (green, leafy).
Cucumber + oniontop 8% of all pairs

Smell alikestrong

Cooked together6,050 recipes

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

Smell alikemoderate

Cooked together4,734 recipes

Shared aroma: 2-methylbutyl acetate (fruit).
Onion + parsleytop 9% of all pairs

Smell alikemoderate

Cooked together25,843 recipes

Shared aroma: 2,4-decadienal (seaweed).

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

What each ingredient does

Cucumbers: Form the bulk of the soup, providing its body and fresh, mild flavor when stewed and pressed.
Onions: Add savory depth and aroma to the stewed base.
Veal stock: Provides the liquid and savory meaty flavor that carries the cucumber purée.
Boiling cream: Adds richness and a smooth, velvety texture to the soup.
Eggs: Optional yolks that further enrich and thicken the soup.

The step that matters

Stew gently until tender. Cooking too hard or too briefly leaves the vegetables either scorched or fibrous, so the pressed purée will be uneven in texture and flavor. Gentle, sufficient stewing lets the cucumber and onion soften fully so they pass easily through the sieve.

Swap the parsley

The recipe marks parsley as optional. How well each one fits the dish's main ingredients (cucumber, onion, veal, cream, pepper, egg, vinegar):

Tarragonfits better
Garlicfits about as well
Parsleythe original
Capersfits about as well

Fit is the average pairing score against cucumber, onion, veal, cream, pepper, egg, 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.