You will have to scale it up but this is my recipe. Very sharp ginger bite, not too sweet.
2 liters of water
4 oz. of Ginger sliced and bruised (smash it with the edge of the blade)
1 Cup of white sugar
approx. 1/4 cup of lime juice (to taste really)
1 tsp of vanilla extract
a dash of cracked
white pepper (gives it some more bite and zing. Complements well I think)
Bring the water, ginger, sugar and pepper to the boil. Reduce heat add lime juice and simmer for 30-40 minutes. Strain out solids. Stir in vanilla extract.
Cool. I then add it to a 2 liter soda bottle set it in the fridge til cold and force carbonate with a homade
carbonater cap
enjoy.