Why it works: Sugar and lemon are a kitchen classic. They rank in the top 18% of all ingredient pairs, and cooks put them together in 53,532 recipes. Both carry 2-nonenal, which smells fatty, green. The science ↓
Boston Cream
Ingredients
Directions
Make the syrup
Boil the water and sugar for 1-2 minutes.
Stir in the tartaric or citric acid.
Flavour and bottle
When nearly cold, add the lemon juice or essence and stir in the beaten egg whites.
Beat well and then bottle the mixture.
Cork the bottles tightly.
Serve
Mix 2-3 tablespoons of the cream with a large half-tumbler of water and about 1 teaspoon of baking soda. Stir and drink.
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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Sugar + lemontop 18% of all pairsSmell alikelowCooked together53,532 recipes
Shared aroma: 2-nonenal (fatty, green).
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Lemon + eggtop 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).
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
- Sugar
- Provides sweetness and body to the drink.
- Tartaric or citric acid
- Adds sharpness that balances the sweetness.
- Lemon juice
- Adds acidity and fresh citrus aroma.
- Egg whites
- Whipped into the liquid to add a light, foamy texture.
- Baking soda (in the method)
- Reacts with acid to release carbon dioxide, giving fizz.
The step that matters
Add the lemon and egg whites when nearly cold. Adding the egg whites to very hot liquid would start to cook them, so they would not blend in and foam well. Letting the mixture cool first keeps the whites smooth and well dispersed.
Swap the lemon
How well each one fits the dish's main ingredients (sugar, egg):
- Vanillafits better
- Raisinfits about as well
- Lemonthe original
- Datesfits less well
Fit is the average pairing score against sugar, egg. 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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