Why it works: Butter and bread match in chemistry and in kitchens. They rank in the top 3% of all ingredient pairs, and 27,145 recipes mention both. Both carry delta-decalactone, which smells sweet, creamy. The science ↓
The recipe
Ingredients
Contains: egg, milk, wheat, fish (auto-detected from the ingredients and method; we can miss things, so check labels)
Directions
Prepare the sardines
Remove the skin from the sardines.
Heat the sardines and place them on fried bread or toast.
Make the sauce
In a saucepan, beat the egg yolks.
Add the butter, tarragon, malt vinegar, mustard, and salt to the egg yolks.
Stir the mixture over low heat until it thickens.
Serve
Pour the sauce over the sardines on the toast.
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.
-
Butter + breadtop 3% of all pairsAroma overlapstrongMentioned together27,145 recipes
Shared aroma: delta-decalactone (sweet, creamy).
-
Tarragon + mustardtop 3% of all pairsAroma overlapstrongMentioned together573 recipes
Shared aroma: methyleugenol (clove, spice).
-
Vinegar + mustardtop 4% of all pairsAroma overlaplowMentioned together14,067 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Tarragon + vinegartop 4% of all pairsAroma overlapmoderateMentioned together1,299 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Egg + breadtop 6% of all pairsAroma overlapstrongMentioned together22,584 recipes
Shared aroma: (e)-2-octenal (fatty, green).
Vinegar and mustard share little aroma chemistry, yet 14,067 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
- Egg yolks
- Emulsify and thicken the sauce as they set over gentle heat.
- Butter
- Adds richness and smoothness, helping the sauce feel silky.
- Malt vinegar
- Adds acidity that sharpens the flavour and balances the rich yolks.
- Sardines
- Provide the oily, savoury fish that forms the base of the dish.
The step that matters
Stir the sauce over low heat until it thickens. Egg yolks thicken through gentle heat; if the heat is too high they can scramble into lumps, so the sauce must be stirred constantly over low heat and removed as soon as it coats a spoon.
Flavor stand-ins for the tarragon
How well each one fits the dish's main ingredients (egg, butter, malt, vinegar, mustard, bread):
- Tarragonthe original
- Cinnamonabout as good a flavor fit
- Celeryabout as good a flavor fit
- Pepperabout as good a flavor fit
Fit is the average pairing score against egg, butter, malt, vinegar, mustard, bread. 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).
“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
Illustration
Illustration
Illustration
IllustrationThe 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.