Rosellas are grown mainly for their calyces, which are the red fleshy outer layer surrounding the seedpods. They have a tart flavour similar to raspberries or rhubarb and are rich in acid and pectin.The calyx is bright red and acid and should be harvested after the sepals close and the seedpod is formed. At this time the calyx measures approximately 3-4 cm in length. In most climates the calyx is ready for picking during autumn. Harvesting should occur while the calyx is tender, crisp, plump and juicy and before any woody tissue develops.
To remove the seed pod for cooking, cut off the very bottom of the calyx and using a finger, push the visible pod up through the top, where the sepals are close together or just peel the calyx off the pod and stem.
Most rosella jam recipes will instruct you to cover the seedpods with water and simmer for 10 minutes, until soft and translucent in appearance and to cook the calyces in the strained liquid. This process extracts pectin from the seedpods to help the jam set, but I have found that there is enough pectin in the calyx to allow setting and the resulting jam will not have the bitter taste associated with cooking the seedpods.
- prepare the fruit for jam making first soak it for a few minutes in a sink full of cold water and then drain.
- separate the red calyx (the fleshy cover surrounding the seedpod) from the seedpod as described above.
- weigh the fruit - you will need an equivalent weight of suger to make the jam.
- weigh the sugar and set aside.
- place the fruit into a large heavy based saucepan - the jam will froth high in the saucepan and it needs to be no more than half full before you start it boiling.
- add a small amount of water (no more than ¼ cup for every kg of fruit)
- simmer gently until the calyces are very soft. Keep an eye on the mixture as you may need to add a little more water to stop the mixture from sticking. The mixture should be quite thick and gloopy.
- add the weighed sugar to fruit and stir over a gentle heat until the sugar is completely dissolved.
- bring to the boil and simmer for 10 minutes.
- skim the froth for a more presentable jam. You can test the jam for setting if you like, but I don’t bother for this cooking method.
- bottle the jam into clean hot jars and seal immediately.
The jam doesn't need to be refrigerated until the bottle is opened. It should keep unopened in the pantry for up to 12 months.