Why it works: Grape and lemon are a kitchen classic. They rank in the top 14% of all ingredient pairs, and cooks put them together in 2,412 recipes. Both carry 3-hexenal, which smells apple, fruity. The science ↓
Water-melon Rind
Ingredients
Directions
Prepare the rind
Cut the watermelon rind into fanciful shapes with a sharp knife.
Weigh the rind and use 1.5 pounds of sugar for every pound of rind.
Soak the rind in weak alum water for three days.
Soak the rind in clear water for 24 hours.
In a kettle lined with grape leaves, layer the rind and cover with water.
Simmer for 2 hours.
Spread the rind on dishes to cool.
Make the syrup
In the kettle, combine sugar and 1 pint of water for every 1.5 pounds of sugar.
Beat the egg whites and add to the kettle.
Boil and skim off the egg whites.
Strain the syrup.
Wipe out the kettle and return the syrup.
Bring to a boil.
Add the rind and cook for 2 hours.
Remove the rind.
Boil the syrup again.
Pour it over the rind.
Finish and pack
The next day, pour off the syrup.
Boil the juice of 1 lemon for every quart of syrup.
When the syrup thickens, pour it over the rind again.
Tie it up.
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.
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Grape + lemontop 14% of all pairsSmell alikemoderateCooked together2,412 recipes
Shared aroma: 3-hexenal (apple, fruity).
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Sugar + lemontop 18% of all pairsSmell alikelowCooked together53,532 recipes
Shared aroma: 2-nonenal (fatty, green).
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Egg + lemontop 19% of all pairsSmell alikelowCooked together44,316 recipes
Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).
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Sugar + eggtop 21% of all pairsSmell alikemoderateCooked together122,807 recipes
Shared aroma: 2-nonenal (fatty, green).
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Sugar + grapetop 23% of all pairsSmell alikelowCooked together7,490 recipes
Shared aroma: beta-damascenone (apple, rose).
Sugar and lemon barely smell alike, yet cooks put them together in 53,532 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
- Watermelon rind
- Forms the bulk of the preserve and takes on the sweet syrup as it cooks.
- Loaf sugar
- Sweetens the preserve and, once concentrated in syrup, preserves the rind.
- Alum water
- Firms the rind so it keeps its shape and stays crisp through long cooking.
- Egg whites
- Collect impurities from the syrup as they coagulate, so they can be skimmed off for clarity.
- Lemon juice
- Adds acidity that brightens the sweetness and helps the syrup thicken.
The step that matters
Soaking the rind in alum water and clear water. Alum firms the rind's pectin-rich tissue so it holds its shape through repeated simmering. Rinsing in clear water afterward removes excess alum, and the long soak must be completed in full for the rind to become properly firm and translucent.
Swap the grape
How well each one fits the dish's main ingredients (sugar, egg, lemon):
- Orangefits better
- Vanillafits better
- Limefits better
- Grapethe original
Fit is the average pairing score against sugar, egg, lemon. 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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