Name: Peruvian Biscuits
Ingredients: 4 oz. flour; 1 lb. rice flour; ½ lb. arrowroot; 1 lb. butter; 1 lb. sugar; 6 eggs; 1 oz. vanilla extract

Why it works: Flour and arrowroot match in chemistry and in kitchens. They rank in the top 2% of all ingredient pairs, and cooks put them together in 525 recipes. Both carry isobutyraldehyde, which smells malty, green. The science ↓

Peruvian Biscuits

Oven, in the book's wordsA moderate oven

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.

Prepare

Preheat your oven to 350°F (175°C).

Shape the dough

In a large bowl, combine the flour, rice flour, arrowroot, butter, sugar, eggs, and vanilla extract to form a dough.
Roll the dough into strips about the thickness of your finger.
Cut the strips into small marble-sized pieces.
Place the pieces on slightly greased baking sheets.

Bake

Bake in the preheated oven until golden.

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 + arrowroottop 2% of all pairs

Smell alikestrong

Cooked together525 recipes

Shared aroma: isobutyraldehyde (malty, green).
Arrowroot + vanillatop 3% of all pairs

Smell alikestrong

Cooked together242 recipes

Shared aroma: coumarin (sweet, hay).
Rice + arrowroottop 8% of all pairs

Smell alikemoderate

Cooked together200 recipes

Shared aroma: coumarin (sweet, hay).
Sugar + vanillatop 8% of all pairs

Smell alikelow

Cooked together35,032 recipes

Shared aroma: beta-damascenone (apple, rose).
Rice + vanillatop 11% of all pairs

Smell alikemoderate

Cooked together1,352 recipes

Shared aroma: guaiacol (smoky, sweet).

Sugar and vanilla barely smell alike, yet cooks put them together in 35,032 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: Adds fat and richness, giving the biscuits a tender, short texture.
Eggs: Bind the dough together and add structure and richness.
Rice flour: Gives a light, crisp, delicate crumb because it contains no gluten.
Arrowroot: Adds starch that helps the biscuits stay tender and crisp.
Sugar: Adds sweetness and helps the surface brown as it bakes.

Swap the arrowroot

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

Arrowrootthe original
Sweet potatofits about as well
Asparagusfits less well
Shallotfits less well

Fit is the average pairing score against flour, rice, butter, sugar, egg, vanilla. 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.