Name: To Pickle Gherkins
Ingredients: gherkins; boiling water; vinegar; tarragon; small silver onions; coarse sea salt; whole pepper

Why it works: Tarragon and pepper match in chemistry and in kitchens. They rank in the top 5% of all ingredient pairs, and 2,399 recipes mention both. Both carry estragole, which smells anise, licorice. The science ↓

To Pickle Gherkins

Ingredients

Directions

Brush or wipe the gherkins clean.
Boil them in plenty of water for a minute.
Quickly transfer them to a large bowl of very cold water and change the water once.
Once cold, drain the gherkins and spread them on sieves to dry in the air.
Place the gherkins in stone jars and cover them with boiling vinegar.
The next day, heat the vinegar again and pour it over the gherkins.
On the following day, add the gherkins to the boiling vinegar for one minute along with tarragon, small silver onions, salt, and whole pepper.

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 aroma chemistry they share, and how many recipes mention both.

Tarragon + peppertop 5% of all pairs

Aroma overlapstrong

Mentioned together2,399 recipes

Shared aroma: estragole (anise, licorice).
Vinegar + tarragontop 7% of all pairs

Aroma overlapmoderate

Mentioned together2,547 recipes

Shared aroma: isobutyraldehyde (malty, green).
Onion + peppertop 11% of all pairs

Aroma overlapmoderate

Mentioned together68,474 recipes

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

Aroma overlapmoderate

Mentioned together1,568 recipes

Shared aroma: coumarin (sweet, hay).
Vinegar + oniontop 14% of all pairs

Aroma overlapmoderate

Mentioned together18,226 recipes

Shared aroma: acetic acid (sour, vinegar).

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 (vinegar, tarragon, pepper):

Mustardbetter flavor fit
Shallotbetter flavor fit
Capsicumbetter flavor fit
Onionthe original

Fit is the average pairing score against vinegar, tarragon, pepper. 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).