As shared by Fran following on from the update about the tonic water kit made by Grainfather below is the homemade tonic recipe.
Homemade tonic Water (cordial) recipe
900mls Water (original recipe 3cups/675ml)
37g Chopped Cinchona bark (original recipe 1oz/28g) (I put mine in a mesh hop/tea bag to be re-used a few times. You can obtain this Cinchona bark online from natural remedy medical places.)
83g citric acid (original recipe 2.2oz/62g)
15g limes (3) – peeled zests only (original recipe 0.4oz/11g)
19g lemon (3) – peeled zests only (original recipe 0.4oz/14g)
19g oranges (2) – peeled zests only (original recipe 0.5oz/14g)
44g (3) stalks lemongrass tops and bottoms trimmed, outer leaves removed then sliced into tiny slices (2.5oz/71g)
5 whole allspice berries (original recipe 4)
4 whole green cardamom pods (original recipe 3)
1.25 tablespoon lavender (original recipe 1)
Combine all ingredients into a large lidded glass jar, put in the fridge and shake once a day for 72 hours (I wrapped mine in a towel in the boot of the car which did the job of daily shaking. Works for any infusions such as limoncello).
Simple sugar syrup
355ml Water (1.5 cups)
600g Natural cane sugar (3 cups/21oz)
Dissolve the sugar over med heat until sugar is dissolved. Cool.
Strain the infusion then strain again through a coffee filter. Add to the syrup. Refrigerate or heat seal this cordial into small bottles.
Use with soda water or sparkling water for the tonic part of gin or just as a lovely non alcoholic drink we call Monic (mock gin & tonic).
Have fun. It doesn’t last long.