Name: Railroad Cake
Ingredients: 2 cups of flour; 1 cup of sugar; ½ cup of sour milk; 2 eggs; 2 tablespoons of butter; 1 teaspoon of cream of tartar; ½ teaspoon of baking soda; lemon zest to taste

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 ↓

Railroad 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. The book gives no cooking times either; the times in the steps were added in transcription, so check for doneness rather than trusting the clock.

Prepare

Preheat the oven to 350°F (175°C).

Make and bake the cake

In a bowl, mix the flour, sugar, sour milk, eggs, butter, cream of tartar, baking soda, and lemon zest until well combined.
Pour the batter into a greased cake pan.
Bake for 25-30 minutes or 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.

Milk + buttertop 7% of all pairs

Smell alikemoderate

Cooked together81,283 recipes

Shared aroma: (z)-4-heptenal (biscuit, cream).
Butter + creamtop 8% of all pairs

Smell alikemoderate

Cooked together41,516 recipes

Shared aroma: delta-dodecalactone (sweet, creamy).
Sugar + creamtop 9% of all pairs

Smell alikemoderate

Cooked together43,450 recipes

Shared aroma: 2,3-butanedione (butter, sweet).
Flour + buttertop 12% of all pairs

Smell alikelow

Cooked together124,287 recipes

Shared aroma: isobutyraldehyde (malty, green).
Flour + milktop 14% of all pairs

Smell alikelow

Cooked together78,219 recipes

Shared aroma: isobutyraldehyde (malty, green).

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

Flour: Provides the main structure that holds the cake together as it bakes.
Eggs: Add structure and richness, helping the batter set as it bakes.
Sour milk: Adds moisture and acidity that reacts with the baking soda to help the cake rise.
Baking soda: Reacts with the acidic sour milk to produce gas that lightens the batter.
Cream of tartar: Adds acidity that supports the baking soda reaction and helps stabilize the batter.
Butter: Adds fat that tenderizes the crumb and contributes flavor.

Swap the lemon

How well each one fits the dish's main ingredients (flour, sugar, milk, egg, butter, cream):

Vanillafits better
Raisinfits better
Coconutfits better
Lemonthe original

Fit is the average pairing score against flour, sugar, milk, egg, butter, cream. 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.