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Sweet Potatoes Au Gratin

Layered sweet potato slices baked with butter, brown sugar, salt, pepper, and buttered cracker crumbs.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 7 ingredients
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Why it works: Sweet potato and pepper are a kitchen classic. They rank in the top 11% of all ingredient pairs, and cooks put them together in 1,015 recipes. Both carry 2-nonenal, which smells fatty, green. The science ↓

Sweet Potatoes Au Gratin

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

  1. Slice the sweet potatoes into ⅓ inch slices.

Layer and bake

  1. Layer the slices in a buttered baking dish.

  2. Sprinkle with coarse sea salt, black pepper, and brown sugar. Dot with butter.

  3. Repeat the layers until all ingredients are used.

  4. Top with buttered cracker crumbs.

  5. Bake at 350°F (175°C) until the crumbs are brown.

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. Sweet potato + peppertop 11% of all pairs
    Smell alikemoderate
    Cooked together1,015 recipes

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

  2. Sweet potato + sugartop 17% of all pairs
    Smell alikemoderate
    Cooked together1,151 recipes

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

  3. Sugar + buttertop 17% of all pairs
    Smell alikemoderate
    Cooked together98,233 recipes

    Shared aroma: guaiacol (smoky, sweet).

  4. Sweet potato + buttertop 20% of all pairs
    Smell alikemoderate
    Cooked together1,491 recipes

    Shared aroma: 2,3-pentanedione (butter, sweet).

  5. Pepper + buttertop 21% of all pairs
    Smell alikemoderate
    Cooked together85,593 recipes

    Shared aroma: trans-2-nonenal (cardboard, fatty).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Sweet potatoes
Form the bulk of the dish and become soft and tender as they cook.
Brown sugar
Adds sweetness and helps the top caramelize and brown in the oven.
Butter
Adds richness and moisture, and helps the crumbs and top brown.
Cracker crumbs
Form a crisp, browned topping over the layers.

The step that matters

Bake until the crumbs are brown. Browning comes from the Maillard reaction and sugar caramelization, which need dry surface heat over time. Pulling the dish too early leaves the topping pale and the sweet potatoes underheated in the center.

Swap the sweet potato

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

  1. Capsicumfits better
  2. Potatofits about as well
  3. Sweet potatothe original
  4. Mustardfits about as well

Fit is the average pairing score against pepper, sugar, butter. 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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