Even senior writer types are mostly too young to remember the soda fountain "phosphates," drinks made with acid phosphate, which is tart, but not tart like citric acid, and tingly, but not effervescent.
Acid phosphate was an attempt to duplicate the mineral waters that bubbled from the ground from natural springs and were considered health-giving. (Nashville's Lockeland Springs, for instance, are lithium salt springs, and bottling the water from them made a few people very rich.) Acid phosphate put the zing and zizzle into health tonics that mimicked mineral water and were the drugs of the drugstore — like early Coca-Cola — and pretty much the best access some people had to medicine.
To quote Mix This, "Some of the most popular soda fountain drinks included the Cherry Phosphate and Chocolate Phosphate, while the local saloon touted the Angostura Phosphate as the perfect remedy for the previous days excesses. There are literally hundreds of phosphate style drinks that haven't been tasted for decades, waiting to be rediscovered."
For you and me, the curious imbibers, acid phosphate is a way to put the sour into sweet-and-sour without also adding citrus. And when you think about it, doesn't every sweet-sour drink you prepare taste
like lemon or lime? Imagine what an interesting change it would be to have a sour that isn't citrus.
Darcy O'Neil, whose blog, Art of Drink, is by turns nerdily and reassuringly scientific, and inspiring for mixologists everywhere while also being not much to look at, wrote a post about acid phosphate last year, and began selling it in liquid form online.
Curious enough to try acid phosphate? Buy it through mixthis.ca, about $12 for 8 ounces, enough for up to 100 drinks. One teaspoon has the souring ability of a large lime, and most recipes call for 1/4 to 1/2 teaspoon.
HT: Tastingtable.com, mixthis.ca and The Art of Drink