Name: Green-butter
Ingredients: ¼ pound butter; 2 handfuls spinach; 6 anchovies; 1 tablespoon curled parsley; 1 teaspoon capers

Why it works: Parsley and capers match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 1,550 recipes. Both carry coumarin, which smells sweet, hay. The science ↓

Green-butter

Ingredients

Directions

Prepare the ingredients

Ice the butter.
Boil the spinach, drain, and pass through a fine sieve to collect the pulp.
Wipe the anchovies free from oil, remove the bones, and pass through a fine sieve to collect the pulp.
Finely mince enough curled parsley to fill a generous tablespoon.
Finely mince enough capers to fill a heaped teaspoon.

Make and chill the butter

Color the butter with spinach pulp, then gradually mix in the anchovy pulp, parsley, and capers until well combined.
Mold the butter into a shape and refrigerate.

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.

Parsley + caperstop 1% of all pairs

Smell alikestrong

Cooked together1,550 recipes

Shared aroma: coumarin (sweet, hay).
Spinach + caperstop 1% of all pairs

Smell alikestrong

Cooked together99 recipes

Shared aroma: coumarin (sweet, hay).
Spinach + parsleytop 5% of all pairs

Smell alikestrong

Cooked together1,025 recipes

Shared aroma: trans-2-hexenal (green, leafy).
Butter + parsleytop 15% of all pairs

Smell alikemoderate

Cooked together28,563 recipes

Shared aroma: trans-2-hexenal (green, leafy).
Butter + caperstop 16% of all pairs

Smell alikemoderate

Cooked together1,637 recipes

Shared aroma: isobutyraldehyde (malty, green).

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

What each ingredient does

Butter: Forms the rich fatty base that carries the other flavors and sets firm when chilled.
Spinach: Supplies the green color and a mild vegetal flavor to the butter.
Anchovies: Add a salty, savory depth that rounds out the butter.