Like most drinks of its kind, this simple soda-fountain classic started as a cure-all tonic for a long list of ailments. Darcy O’Neil, the chemist and bartender who revived the drink in his 2010 book Fix the Pumps (the drink originally appeared in R. de Fleury's 1800 and All That - Drinks Ancient and Modern), makes his own lemon syrup. A commercial version, such as the one made by Monin, can be substituted. O’Neil also makes acid phosphate, which can be purchased via his website, artofdrink.com.
1 oz. lemon syrup
1 tsp. Angostura bitters
½ tsp. acid phosphate
Chilled soda water
Ice cubes, optional
Combine syrup, bitters and acid phosphate in a highball. Add ice cubes if desired. Top with chilled seltzer. Serve with a straw.
For the lemon syrup: Combine 2 tsp. gum arabic and 1/2 tsp. lemon oil with 2 tsp. sugar. Set aside. Dissolve 1 cup sugar in the juice of 8 lemons. Add the gum arabic mixture to the lemon juice mixture and dissolve, heating if necessary.
Adapted from Darcy O’Neil’s Fix the Pumps
Read more about phosphates and the soda fountains that are using them in "Fizzy Business" from the July/August 2011 issue.