Name: Sardine Sandwiches
Ingredients: sardines; hard boiled eggs; salt; cayenne pepper; lemon juice; olive oil or melted butter; buttered bread

Why it works: Pepper and lemon match in chemistry and in kitchens. They rank in the top 3% of all ingredient pairs, and cooks put them together in 27,047 recipes. Both carry trans-2-nonenal, which smells cardboard, fatty. The science ↓

Sardine Sandwiches

Ingredients

Directions

Remove skin and bones from sardines and mash them into a paste.
Mix the mashed sardines with an equal quantity of yolks from hard boiled eggs, rubbed through a wire sieve.
Season the mixture with salt, cayenne pepper, and a few drops of lemon juice.
Moisten the mixture with olive oil or melted butter.
Spread the mixture between thin slices of buttered bread.

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 + lemontop 3% of all pairs

Smell alikestrong

Cooked together27,047 recipes

Shared aroma: trans-2-nonenal (cardboard, fatty).
Lemon + olivetop 7% of all pairs

Smell alikemoderate

Cooked together11,922 recipes

Shared aroma: 3-hexenal (apple, fruity).
Olive + breadtop 9% of all pairs

Smell alikemoderate

Cooked together1,091 recipes

Shared aroma: 2-undecenal (sweet).
Pepper + olivetop 11% of all pairs

Smell alikemoderate

Cooked together30,263 recipes

Shared aroma: 2,4-decadienal (seaweed).
Egg + breadtop 13% of all pairs

Smell alikemoderate

Cooked together22,662 recipes

Shared aroma: (e)-2-octenal (fatty, green).