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Dessert

Rock Biscuits

A sweet biscuit made with egg whites, blanched almonds, candied orange peel, and powdered sugar.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 4 ingredients
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Why it works: Almond and orange are a kitchen classic. They rank in the top 6% of all ingredient pairs, and cooks put them together in 3,125 recipes. Both carry 2,4-decadienal, which smells seaweed. The science ↓

Rock Biscuits

Oven, in the book's wordsA slack oven

Ingredients

Directions

The book says “a slack oven”. The 300°F (150°C) in the steps is the modern equivalent, not the book's own figure.

Prepare the mixture

  1. Whisk the egg whites in a pan until broken up.

  2. Add the sliced almonds, chopped candied orange peel, and powdered sugar to the eggs.

  3. Mix well, adding more almonds and sugar if needed to bind the mixture.

Shape and bake

  1. Line iron plates with white wax paper.

  2. Spoon the mixture onto the paper in biscuit shapes about the size of a half-crown, piled 1 to 1.5 inches high.

  3. Bake in a slow oven at 300°F (150°C) until light in color.

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.

  1. Almond + orangetop 6% of all pairs
    Smell alikemoderate
    Cooked together3,125 recipes

    Shared aroma: 2,4-decadienal (seaweed).

  2. Almond + sugartop 18% of all pairs
    Smell alikemoderate
    Cooked together15,679 recipes

    Shared aroma: 1-penten-3-one (fish, pungent).

  3. Orange + sugartop 20% of all pairs
    Smell alikelow
    Cooked together19,212 recipes

    Shared aroma: beta-damascenone (apple, rose).

  4. Egg + sugartop 21% of all pairs
    Smell alikemoderate
    Cooked together122,807 recipes

    Shared aroma: 2-nonenal (fatty, green).

  5. Egg + almondtop 25% of all pairs
    Smell alikemoderate
    Cooked together12,645 recipes

    Shared aroma: 2,4-decadienal (seaweed).

Orange and sugar barely smell alike, yet cooks put them together in 19,212 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

Egg whites
Whisked to bind the mixture and give the biscuits their light, airy structure.
Sweet almonds
Provide body and a chewy, nutty texture in the finished biscuits.
Candied orange peel
Adds sweetness and a bright citrus aroma throughout the biscuits.
Powdered loaf sugar
Sweetens the mixture and helps it bind together with the egg whites.

The step that matters

Piling the biscuits. Shaping them into mounds about 1 to 1.5 inches high, rather than spreading them flat, keeps the centers moist and the outsides lightly crisp. The mixture needs enough almonds and sugar to bind, so it holds its shape in the oven.

Swap the orange

How well each one fits the dish's main ingredients (egg, almond, sugar):

  1. Vanillafits better
  2. Raisinfits better
  3. Figfits better
  4. Orangethe original

Fit is the average pairing score against egg, almond, sugar. 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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