1 Rinse a screw-top jar (200 ml capacity) (approximately 3/4 cup capacity) and lid in a pot of boiling water and leave upside down to dry on a kitchen towel.
2 Pick over the raspberries and put in a tall vessel.
3 Peel the ginger, grate finely and add to the raspberries.
4 Add the jam sugar to the vessel and puree with an immersion blender for about 10 minutes, until the mixture begins to set.
5 Pour through a small funnel into the prepared jar and seal immediately. Refrigerate and use within 4-5 days.