Name: Citron Tumbler Cake
Ingredients: 5 cups flour; 1 cup chopped citron; 4 eggs; 1 teaspoon baking soda; lemon flavoring

Why it works: Flour and egg are a kitchen classic. They rank in the top 15% of all ingredient pairs, and cooks put them together in 106,462 recipes. Both carry isobutyraldehyde, which smells malty, green. The science ↓

Citron Tumbler Cake

Ingredients

Directions

The book gives no oven temperature. The 350°F (175°C) in the steps was added when the recipe was transcribed, as a starting point.

Prepare

Preheat the oven to 350°F (175°C).

Make the batter

In a large bowl, combine the flour, chopped citron, and baking soda.
In another bowl, beat the eggs and add them to the dry ingredients.
Flavor the mixture with lemon.
Mix until well combined and pour into a greased cake pan.

Bake

Bake until a toothpick inserted in the center comes out clean.

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 their aromas overlap, and how often cooks already put them together.

Flour + eggtop 15% of all pairs

Smell alikelow

Cooked together106,462 recipes

Shared aroma: isobutyraldehyde (malty, green).
Flour + lemontop 17% of all pairs

Smell alikemoderate

Cooked together30,404 recipes

Shared aroma: isobutyraldehyde (malty, green).
Egg + lemontop 19% of all pairs

Smell alikelow

Cooked together44,316 recipes

Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).

Flour and egg barely smell alike, yet cooks put them together in 106,462 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

Flour: Forms the main structure of the cake crumb.
Eggs: Add structure and moisture, helping the batter set as it bakes.
Baking soda: Reacts with acidic ingredients to produce gas that helps the cake rise.
Chopped citron: Adds citrus-peel flavour and pieces of candied fruit throughout the cake.