We had some mandarines in the fruit bowl that we needed to use, so we juiced and used them in general accordance with our ginger beer recipe. The result is a deliciously sweet and refreshing mandarine soda.
For a 3.7L batch, we juiced 16 large mandarines and poured the juice several times through a sieve to remove as much pulp as possible. The juice was then combined with 400g of sugar, 2 large tablespoons of golden syrup, 3 teaspoons of dried ginger powder, 1 teaspoon of mixed spice, 1/2 a teaspoon of citric acid, and a pinch of cream of tartar (all put in a big pot and heated to 80C). This was then topped up with water, decanted in to bottles, and then some ginger beer plant was added.
The bottles were left uncapped overnight, and then sealed the next day. Within 8 hours the bottles were hard and carbonation had obviously occurred. We have since kept them in the fridge, so as to keep them cool prior to serving (to avoid gushing).