Why it works: Flour and butter are a kitchen classic. They rank in the top 12% of all ingredient pairs, and cooks put them together in 124,287 recipes. Both carry isobutyraldehyde, which smells malty, green. The science ↓
Mocha Cake
Ingredients
Directions
The book says “a moderate oven”. The 350°F (175°C) in the steps is the modern equivalent, not the book's own figure.
Make the cake
Separate the yolks and whites of the eggs into different bowls.
Add the sugar to the yolks and beat until creamy.
Sift the flour and baking powder together.
Whip the egg whites to a stiff froth.
Gently fold the flour and whipped whites into the yolk and sugar mixture.
Butter a cake tin, pour in the mixture, and bake at 350°F (175°C) for about 30 minutes.
Once cooked, turn the cake onto a sieve to cool.
Ice and decorate
In a bowl, cream the butter and icing sugar until soft.
Add coffee essence gradually until the icing reaches the desired color and consistency.
Cover the cooled cake with the icing and decorate using a piping bag.
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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Flour + buttertop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Sugar + flourtop 15% of all pairsSmell alikemoderateCooked together92,116 recipes
Shared aroma: phenylacetaldehyde (hawthorne, honey).
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Egg + flourtop 15% of all pairsSmell alikelowCooked together106,462 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Egg + buttertop 17% of all pairsSmell alikemoderateCooked together118,967 recipes
Shared aroma: decanal (soap, orange peel).
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Sugar + coffeetop 17% of all pairsSmell alikelowCooked together4,344 recipes
Shared aroma: beta-damascenone (apple, rose).
Flour and butter 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
- Eggs
- Whites trapped as a stiff foam give the cake its light, airy structure, and yolks add richness.
- Baking powder
- Releases gas in the batter during baking, helping the cake rise.
- Flour
- Its proteins set during baking, giving the cake its firm structure.
- Butter
- Adds fat for tenderness and flavor, and makes the icing soft and spreadable.
- Castor sugar
- Sweetens the batter and helps create a soft, tender crumb when beaten with the yolks.
- Icing sugar
- Sweetens the icing and gives it a smooth, fine texture when creamed with butter.
The step that matters
Folding the whipped whites into the yolk mixture. Folding gently keeps the air bubbles in the whipped egg whites. Stirring or beating would deflate the foam, leaving a denser cake that rises less.
“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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