1 kg chopped rhubarb
50g finely sliced root ginger
2 star anise
Zest from medium orange
500ml water
600g sugar
10g citric acid per litre

Simmer rhubarb, ginger, star anise and zest in water for 5 – 10 mins until the rhubarb collapses. Then allow to cool in the pan. Strain through a jelly bag or muslin, then add 600g sugar and 10g of citric acid per litre of strained liquid. Reheat gently to about 85°C to dissolve the sugar.  Bottle hot to preserve.  To use, dilute to taste.