Take your ginger out of the freezer and wait for it to thaw slightly. Freezing the ginger makes it much easier to peel, and also breaks down the cell structure and helps to tenderise it.
Wash and rinse your jar(s) and put into a warm oven 50 °C -100 °C upside down to dry and sterilise.
Peel the thawed ginger with the ball end of a teaspoon and cut into chunks of the size you prefer.
Put in a pan and cover with cold water. Bring to the boil and simmer for 30 minutes.
Drain over a jug and reserve the cooking water.
Put 375ml of the cooking water back into the pan (add more water if you need to). Add the sugar and heat until the sugar is dissolved. Add the ginger back in, reduce heat and cook until tender (approx. 30 minutes).
Spoon the ginger in the jars and then cover with the syrup from the pan, make sure that the ginger is submerged in the syrup. Leave for 3 weeks to develop the flavour.
Use any leftover syrup in drinks – add to sparkling water or to cocktails. It is also delicious with porridge or over ice cream.