Tonic Water Safe Quinine Levels

Hebden

Hi all,
I'm going to try and contribute something useful to the site for once. Lots of people here must be producing gin and therefore some are producing tonic to acompany it. Tonic water is made with Quinine which has potential negative side effects, therefore the FDA has limited Quinine in tonic water to 83 parts per million (ppm)
I have decide to make my own tonic water and wanted to be safe, not tried the tonic water end product yet, but will share the recipe and the mathematics.
The Quinine in Tonic water is derived from Cinchona Bark. The concentration of Quinine in Cinchona Bark is <5%, if you want the most accurate reading of quinine in your end product, your best using powder.
If you purchased bark, you can grind it in a coffee grinder or you can use bark, it is unlikely that you will extract more quinine from bark than you will from powder, so this will be safe to use as a substitute, but your quinine levels in your product will likely be lower than if you had used powder.
The Recipe:
•4 cups water
•1/4 cup (1 ounce/20 grams) cinchona bark, powdered (use a coffee grinder)
•1/4 cup citric acid, also known as lemon salt
•3 limes, only the peeled zests
•3 lemons, only the peeled zests
•1 grapefruit, only the peeled zests
•1 cup chopped lemongrass (3-4 stalks)
•9 whole allspice berries
•6 whole cardamom pods
•1/4 teaspoon kosher salt
•1 tablespoon lavender
•Simple syrup
two parts sugar to one of boiling water, I suggest 4 sugar, 2 water & 1/4 tsp citric acid stirred to dissolve, simmer until 240f
Method
•In a covered saucepan, bring all ingredients except the simple syrup to a boil and reduce heat immediately; simmer on low for a half hour, then remove from heat and allow to cool fully.
•Transfer to a carafe or jar and chill for two days.
•Strain through a superfine chinois or cheesecloth, or by using a plunger press coffee maker.
•Return to the carafe and refrigerate for a day or two, allowing sediment to accumulate on bottom.
•When the layer of sediment seems stable, gently decant off the clearer liquid without disturbing the sediment “mud.”
•It should be about 3 cups at this point (I was closer to 2 1/2); add to this liquid an equal measure of simple syrup, mixing well. Funnel into a clean, cappable bottle and refrigerate.
•Makes roughly 6 cups or 1.5 liters. This will vary and so will your maths.
Quinine Levels:
So the recipe uses 20g Cinchona @~5% Quinine - YOU HAVE 1g Quinine in your final product "whatever the volume".
Source: /pic/sjqtncynxsw.html ... water.html
To calculate down to 83ppm in your Tonic Water:-
Ppm Calculation
•(1g / finished product volume) * 1,000,000 = ppm
•So say your simmered ingredients = 625ml + your simple sugar = 625ml = 1,250ml finished product of Qunine Syrup
•(1g / 1,250) * 1,000,000 = Quinine Syrup @ 800ppm
This is just the Quinine Syrup ppm though, your finished tonic is a combination of Quinine Syrup + Soda, so the maths continues.
For me, I have a soda stream which has 1L bottles which I will use to make my carbonated Tonic water in. 1L of tonic is plenty for my average gin session even if I have a heavy night, but if I have guests, you’ll have a spare 1L bottle.
So I want to mix Quinine Syrup + Soda to make 1L of tonic at 83 ppm, maths:-
•800ppm / 83ppm = 9.64:1 ratio (total 10.64 parts)
•That means you need 964ml Soda to 100ml Quinine Syrup to = 83ppm Quinine in your tonic
•1,000ml end product tonic / 10.64 = 906ml Soda : 94ml Quinine Syrup = 9.64:1 = 83ppm
EDIT: I would just like to add that Quinine is insoluble in water, it is soluble in ethanol.!
And so:-
You could extract the quinine using by infusing say 100ml strong ethanol to said 20g cinchona powder before adding it to
recipes whereby Quinine is added to a water based pre-sugar syrup stage of a recipe. That would make it a 3 stage cook but would result in a higher likelihood of quinine entering your tonic at calculated levels.
(but your tonic would now be alcoholic).

If there are any mistakes, please let me know and I will edit the original post.