Why it works: Milk and butter are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 81,283 recipes. Both carry (z)-4-heptenal, which smells biscuit, cream. The science ↓
Vassar Fudge
Ingredients
Directions
Cook the mixture
Combine sugar, milk, chocolate, and butter in a saucepan.
Boil until the mixture hardens when dropped into water.
Finish and serve
Remove from heat and stir until nearly cool and smooth.
Spread the fudge on plates.
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.
Photo for illustrative purposes only · Contact us to use it
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.
-
Milk + buttertop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
-
Sugar + chocolatetop 13% of all pairsSmell alikemoderateCooked together15,404 recipes
Shared aroma: guaiacol (smoky, sweet).
-
Milk + chocolatetop 13% of all pairsSmell alikemoderateCooked together9,128 recipes
Shared aroma: gamma-nonanolactone (coconut, sweet).
-
Chocolate + buttertop 16% of all pairsSmell alikemoderateCooked together10,543 recipes
Shared aroma: delta-decalactone (sweet, creamy).
-
Sugar + buttertop 17% of all pairsSmell alikemoderateCooked together98,233 recipes
Shared aroma: guaiacol (smoky, sweet).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Sugar
- Provides sweetness and forms the crystal structure that gives fudge its body.
- Milk
- Adds moisture and dissolved milk solids for a creamy, soft texture.
- Chocolate
- Supplies the chocolate flavor, color, and some fat.
- Butter
- Adds fat that makes the fudge smoother and richer.
The step that matters
Boil until the mixture hardens when dropped into water. Cooking sets how much water evaporates and how concentrated the sugar becomes. Stopping too early leaves fudge soft and runny, while going too far makes it hard and grainy.
“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.
More fudge recipes
You might also like
The free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.

Chocolate Cream171 recipes
Chocolate Cookies76 recipes
Chocolate Drop Cookies50 recipes
Chocolate Cake32 recipes