Lemon Egg Phosphate, the Soda Fountain Sour
Reader ratingsLemon syrup, a whole egg and half a teaspoon of acid phosphate, shaken with ice and topped with soda: the soda fountain’s sour drink from What to Drink (1920).
- Recipe makes
- About 1 1/4 cups lemon syrup, enough for 6 drinks
- Prep
- Cook
- Total
Includes about 30 minutes for the lemon syrup to cool. Each drink then takes a couple of minutes.
Lemon egg phosphate in a tall glass, finished with grated nutmeg.
The story behind the recipe
A phosphate was the soda fountain’s sour drink, sharpened with acid phosphate from the druggist’s shelf, and at one big drugstore chain in 1921 it was the cheapest drink on the counter. At the Dow fountains in Cincinnati, The Soda Fountain reported that September, “the very cheapest drink served is any one of the phosphates, offered now at ten cents, including war tax.” Ten cents then is about $1.80 now, by US consumer prices. The egg phosphate was the same drink with a whole egg shaken in.
A bowl of eggs on the counter
Thompson’s Spa on Chestnut Street in Philadelphia had, the magazine says, “for many years enjoyed fame as a temperance center,” and its fountain was known for “the real excellence of its egg and phosphate drinks.” Its manager described the house style in the same issue: “In our egg phosphate we never use any vanilla, or pineapples, nothing but lemon.” To remind customers, the fountain kept “a large glass bowl heaped up with eggs” at the end of the counter nearest the street. Every drink went out in a ten-ounce glass.
Bertha Stockbridge brought the drink home in What to Drink (1920). Her lemon egg phosphate takes three tablespoons of lemon syrup, an egg and half a teaspoon of acid phosphate, shaken with a little ice, then filled with soda, strained into a tall glass and finished with grated nutmeg. She never explains the acid. She says only: “Acid phosphate may be purchased at any drug store.”
Read more about this recipe
The acid and the egg today
Acid phosphate is still made for drinks: phosphoric acid in water, partly neutralized with calcium, magnesium and potassium phosphates. One seller puts its acidity at about that of lime juice and sells it to add sourness without a fruit flavor of its own. Buy one sold as a drink ingredient, and never use laboratory or concentrated phosphoric acid in its place.
The egg goes in raw, so use a pasteurized one. Shaken hard, it turns lemon syrup and soda into a pale, foamy drink with a head that holds the nutmeg. Winter fountains served a hot cousin, Hot Egg Lemonade, with the egg, lemon syrup and acid phosphate filled up with hot water.
Recipe makes: About 1 1/4 cups lemon syrup, enough for 6 drinks
Ingredients
For About 1 1/4 cups lemon syrup, enough for 6 drinks. Quantities are shown as written.
Quantities as written here, for About 1 1/4 cups lemon syrup, enough for 6 drinks.
Lemon syrup
- Sugar1 1/8 cups
- Water4 fl oz
- Lemon juice2 fl oz
Per drink
- Lemon syrup3 tbsp
- Pasteurized egg1
- Acid phosphate1/2 tsp
- Cracked ice1 tbsp
- Soda water, chilled6 fl oz
- Grated nutmeg, to finish
Measurement notes
Ingredients as written here
- 1 1/8 cups sugar
- 4 fl oz water
- 2 fl oz lemon juice
- 3 tbsp lemon syrup
- 1 pasteurized egg
- 1/2 tsp acid phosphate
- 1 tbsp cracked ice
- 6 fl oz soda water, chilled
- grated nutmeg, to finish
Equipment
Small saucepan
Clean bottle or jar for the syrup
Cocktail shaker and strainer
Tall straight glass, about 12 fl oz
Nutmeg grater
Instructions
For the syrup, put the sugar and water in a small saucepan and stir over medium heat until the sugar has dissolved. Bring to a boil and boil gently for 2 minutes.
Add the lemon juice, boil for 1 minute more, then take the pan off the heat. Leave to cool for about 30 minutes and pour into a clean bottle.
For each drink, put the cracked ice, pasteurized egg, the lemon syrup and the acid phosphate in a cocktail shaker. Close it and shake hard for about 15 seconds, until the egg is frothy.
Strain into a tall straight glass, pour in the very cold soda water slowly to fill it, and grate a little nutmeg over the top. Serve at once.
Nutrition
200calories per serving
- Recipe makes
- About 1 1/4 cups lemon syrup, enough for 6 drinks
- Servings
- 6
Estimated from USDA FoodData Central values for sugar, lemon juice and a whole egg, for one drink with 3 tablespoons of the syrup.
Recipe notes
When adjusting quantities
Scale the lemon syrup ingredients together. The drink ingredients are for one glass; multiply them by the number of drinks.
Notes
Quantities mentioned in these notes don’t change when you adjust the batch.
Stockbridge’s lemon syrup (p. 73) is 4 pounds of sugar, 1 quart of water and 2 cupfuls of lemon juice, boiled for ten minutes and then five more with the juice. This version is one-eighth of her batch. A small batch thickens much faster, so it boils for only 3 minutes in all.
Her drink (p. 133) gives no soda amount: “fill with soda.” 6 fl oz fills a 12 fl oz glass. She adds the soda before straining; here the shaken mixture is strained first and the soda poured onto it in the glass, so less of the fizz is lost. With so little ice in the shaker, the soda needs to be very cold.
Acid phosphate is sold online by bar suppliers, already diluted and ready to use: a weak solution of phosphoric acid and mineral salts, about as sour as lime juice (pH around 2), measured by the half teaspoon. Buy a food-grade product sold for drinks, with its ingredients on the label. Never use phosphoric acid itself, whether a laboratory or industrial grade or the 75 to 85 percent food-grade concentrate sold to manufacturers: at that strength it burns, and no home dilution makes it a substitute.
Without acid phosphate the drink loses its sharp edge; adding 2 teaspoons of lemon juice is our substitute, and it makes the drink taste more of lemon.
The phosphate takes its turn at the party in Five Alcohol-Free Drinks for a 1920s Party.
Storage
Keep the lemon syrup in a clean, closed bottle in the fridge.
Scaling changes the ingredients only; glassware, ice and timings need their own judgment. To adapt this recipe further, try the recipe tool at TuneMyRecipe (opens in a new tab), our sister site.
Sources and attribution
Bertha E. L. Stockbridge, What to Drink: The Blue Book of Beverages (New York and London: D. Appleton and Company, 1920), pp. 73 and 133
See the original pages (scan at Internet Archive) (opens in a new tab)
Recipe details
- Drink
- Alcohol-freeMocktail
- Drink family
- Sodas & Soft Drinks
- Region
- American
- Source decade
- 1920s
- Base
- Fruit & juice
- Difficulty
- Easy
- Occasion
- 1920s party