Why it works: Chocolate and walnut are a kitchen classic. They rank in the top 10% of all ingredient pairs, and cooks put them together in 1,548 recipes. Both carry 3-ethyl-2,5-dimethylpyrazine, which smells roasted, nutty. The science ↓
Chocolate Bars
Ingredients
Directions
The book says “a very slow oven”. The 300°F (150°C) in the steps is the modern equivalent, not the book's own figure.
Make the batter
Cream the butter and sugar together.
Add the beaten eggs and mix well.
Incorporate the flour into the mixture.
Melt the chocolate and add it, mixing thoroughly.
Fold in the chopped walnut meats.
Bake and cut
Spread the mixture about ½ inch thick in a buttered tin.
Bake for 30 minutes in a slow oven at 300°F (150°C).
The bars should be a little sticky when first baked.
Cut into bars after cooling.
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.
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Chocolate + walnuttop 10% of all pairsSmell alikemoderateCooked together1,548 recipes
Shared aroma: 3-ethyl-2,5-dimethylpyrazine (roasted, nutty).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Flour + walnuttop 12% of all pairsSmell alikemoderateCooked together5,873 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Sugar + chocolatetop 13% of all pairsSmell alikemoderateCooked together15,404 recipes
Shared aroma: guaiacol (smoky, sweet).
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Walnut + meattop 13% of all pairsSmell alikemoderateCooked together1,035 recipes
Shared aroma: 2,4-decadienal (seaweed).
Butter and flour barely smell alike, yet cooks put them together in 124,287 recipes: they 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
- Butter
- Creams with sugar to trap air and add richness and tenderness to the bars.
- Sugar
- Creams with butter and adds sweetness while helping the bars brown and stay moist.
- Eggs
- Bind the batter and add structure and moisture as they set in the oven.
- Pastry flour or ordinary flour
- Provides the structure that holds the bars together as the batter sets.
- Baker's chocolate
- Adds deep chocolate flavour and fat that gives the bars a dense, fudgy body.
- Walnut meats
- Add crunch and a nutty flavour that contrasts with the soft, dense batter.
The step that matters
Baking time and oven heat. Baking at the stated slow oven heat for the stated time sets the batter gently. Overbaking dries the bars and makes them crumbly, while the record notes they should still be a little sticky when first baked.
Swap the walnut
How well each one fits the dish's main ingredients (butter, sugar, egg, flour, chocolate, meat):
- Almondfits better
- Pecansfits about as well
- Walnutthe original
- Chestnutfits about as well
Fit is the average pairing score against butter, sugar, egg, flour, chocolate, meat. Candidates are from the same food group and used in at least 100 recipes.
“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.
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