For a while now I’ve been searching for academic looks at tonic water and have come up dry. How could something so economically significant be so poorly written about? Finding something useful would help keep tonic water’s renaissance going. A newly acquired book, Carbonation (1959) by the flavor chemist Morris Boris Jacobs has some small notable factoids.
e. Quinine Water
A specialty-flavored beverage that has had considerable vogue in Great Britain and has had some popularity in the United States recently is quinine water. In the Soft Drinks Minimum Standard (Food Standards [Soft Drinks] Order, 1953, 1828) of Great Britain which came into effect on December 20, 1953, the standards that had been in force for “Indian and Quinine Tonic” were continued. These standards required that there is a minimum of 1 pound 2 ounces of sugar per 10 gallons, a maximum of 82 grains of sacharin per 10 gallons, and a minimum of 0.5 grain of quinine (calculated as quinine sulfate) per pint. These standards should prove of assistance in the formulation of a flavored sirup for the manufacture of this type of specialty-flavored beverage.
Another quinine water or tonic formulation contains 8 grains of quinine sulfate in a mixture of 4 pints of carbonated lemon soda and 4 pints of carbonated water, that is, 1 grain of quinine sulfate per pint of finished beverage.
1 grains = 0.06479891 grams
1 pint = 473.176 mL
So that recommendation of 1 grain per pint, metrically is 0.1369 grams of quinine sulfate per liter of soda.
0.137 g/L quinine sulfate.
Lets see how these numbers compare to numbers from Avery Glasser of Bittermans that were quoted here by Tess Posthumus.
Avery is known from Bittermens, a company making bitters, extracts, liqueurs and more. He works a lot with cinchona bark and discovered that cinchona bark consists 5% out of quinine. The American federal safety standard for the use of quinine is a maximum of 83 parts of quinine per million in a drink. The average commercial tonic water has 2.48 mg quinine per 30ml.
Avery’s numbers supposedly come from here. (But I guess I haven’t read enough about this topic if it took me so long to find that out). 2.48 mg per 30 ml is 0.083 g/L which is far less than the 0.137 g/L from Jacobs, but maybe people were tougher back then. Numbers from the old literature give the percent of quinine sulfate in Java Cinchona as 5-7% which is inline with Avery’s 5%, but who knows what it is these days after decades of improvements.
Glasser’s numbers and Jacobs numbers are very different. I’ve never really been interested in tonic water but it looks like I need to order some quinine sulfate and attach a sensory experience to the numbers.
[edited to add: A potential difference between Avery’s and Jacobs’ numbers could be the salt form of quinine sulfate used by Jacobs and the free base form of quinine sulfate which could be what Avery is quoting. A salt is when a particular acid and base are combined while the free base is when the base is separated from the acid. The free base number is the most specific while the salt number could vary significantly depending on what acid forms the salt. I bet if I did more reading I could get to the bottom of all this.]
(Me, in the bostonapothecary laboratory assaying quinine)
What I suspect is that cinchona added to tonic water is and has always been in the form of purified quinine sulphate. People making tonic water from raw unpurified cinchona are just far from the mark. M.B. Jacobs gives us a best bet and that is 137 mg/L.
There are more gems in the book, but I lent it out before I could digitize them. So more to come!