1 Rinse screw-top jars (each 400 ml) (each approximately 1 3/4 cups) and lids in a pot of boiling water and allow to dry upside down on a clean kitchen towel.
2 Squeeze juice from the oranges and measure out 1200 ml (approximately 5 cups) juice.
3 Pass the measured juice through a fine sieve into a pot.
4 Halve the vanilla bean lengthwise, scrape out the seeds and add seeds to the pot along with the jam sugar.
5 Rinse thyme, shake dry and add to the pot along with the vanilla pod. Bring to a boil and cook over high heat, stirring constantly, 5-7 minutes, skimming off foam from surface.
6 Test setting point by placing a few drops of hot liquid on a small plate. If the liquid begins to set after a few seconds it can be jarred. Otherwise, continut to cook for another 1-2 minutes and repeat the test.
7 Remove the vanilla pod and thyme. Pour the hot mixture through a funnel into the prepared jars. Seal immediately, then turn upside down and let rest on a damp cloth for 5 minutes before turning right side up and letting cool completely. Tip: To preserve the jelly for longer, you will need to process the jars according to manufacturer's instructions, or visit http://nchfp.uga.edu/.