Name: Boston Cream
Ingredients: 1 lb sugar; ½ lb tartaric acid; 1 teaspoon ginger; 1 teaspoon essence of lemon; Whites of 3 eggs

Why it works: Ginger and lemon match in chemistry and in kitchens. They rank in the top 5% of all ingredient pairs, and cooks put them together in 5,154 recipes. Both carry beta-phellandrene, which smells minty, terpene. The science ↓

Boston Cream

Ingredients

Directions

Make the syrup

Boil the sugar with 6 cups of water.
Strain the mixture over the tartaric acid.

Flavour and bottle

When cool, add the essence of lemon, beaten egg whites, and ginger.
Bottle the mixture.

Serve

To serve, fill a tumbler one-third full with the mixture, add cold water, and a pinch of baking soda to effervesce.

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.

Ginger + lemontop 5% of all pairs

Smell alikestrong

Cooked together5,154 recipes

Shared aroma: beta-phellandrene (minty, terpene).
Sugar + gingertop 17% of all pairs

Smell alikelow

Cooked together14,054 recipes

Shared aroma: 1-penten-3-one (fish, pungent).
Sugar + lemontop 18% of all pairs

Smell alikelow

Cooked together53,532 recipes

Shared aroma: 2-nonenal (fatty, green).
Lemon + eggtop 19% of all pairs

Smell alikelow

Cooked together44,316 recipes

Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).
Sugar + eggtop 21% of all pairs

Smell alikemoderate

Cooked together122,807 recipes

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

Sugar and ginger barely smell alike, yet cooks put them together in 14,054 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 syrup base of the drink.
Tartaric acid: Adds sharp acidity and, with baking soda, produces the fizz when serving.
Eggs: Whites are beaten in to add a light, foamy texture to the drink.