At first everything was manual. A soda jerk pumped some syrup into a glass, added carbonated water, (and perhaps ice cream for a root beer float, etc.), then handed the glass across the counter to his customer.
We don’t drink very many soft drinks other than in summer, so at home we keep a two-liter bottle of carbonated water (club soda) in the refrigerator and some Torani or DaVinci syrups. Club soda is added at about an 8:1 dilution ratio to syrup. If we drank a lot more, then maybe we’d buy a SodaStream carbonator machine using concentrated syrups with a 24:1 ratio.
Later came the self-serve fountains with a choice of eight flavors or so. Each dispensing head automatically mixed carbonated water (or plain water) with syrup in the correct 5:1 ratio to produce a drink. Syrups were dispensed from five-gallon bag-in-box (BIB) cartons hidden in a back room or basement.
About five years ago Coca Cola developed the sleek Coke Freestyle soda fountain which is capable of producing over 100 flavors (like the number of tune selections in a jukebox). It has computerized touch-screen controls. At the single dispensing head it mixes flavoring, sweetener, and carbonated water (or plain water). Flavorings are in 46-ounce cartridges rather than the five-gallon (640 ounce) syrup boxes previously used. (Dean Kamen, inventor of the Segway was involved in their development). That’s almost 14 times more concentrated, or a ratio of about 70:1.
There are three rows of cartridges. The top row contains dark ones, and the Freestyle shakes them ten seconds every two minutes to keep their contents from settling. Sweetener for diet drinks (NNS) also is inside the machine at the lower right. Sweetener for regular drinks (HFCS) still is dispensed from a pair of bag-in-box cartons hidden in a back room or basement. The self-serve version of the Freestyle even has an RFID tag reader for identifying a new cartridge before it is installed. (If it is a dark flavoring, the row gets shaken for a minute before use). You can get a regular Coke, or a vanilla or cherry one, (or even orange or raspberry). There even are custom mix flavors connected with music groups:
“....look for Lady Antebellum on the Coca-Cola Freestyle® machine. Try any of the 3 exclusive Lady Antebellum mixes to enter for a chance to win a grand prize trip to a Lady Antebellum concert and other great prizes!”
Are there more concentrated flavorings than in the Coke Freestyle? Look at the pocket-sized container of Minute Maid water enhancer drops. It gets mixed at a ratio of 96:1. That is 32 times higher than their frozen orange juice concentrate, mixed at 3:1. Another brand, Mio Liquid Water Enhancer, has an even higher 118:1 ratio. Finally, syrups for making snow cones from shaved ice may have a ratio of 192:1.
A bar chart summarizes the wide range of ratios for all these concentrates, syrups, and flavorings. (Click on it to see a larger, clearer view).
Images of a jukebox and 1936 soda jerk came from the Library of Congress.