Using a hand mixer or immersion blender puree the mangoes making sure to leave a few chunks intact.
Pour the mangoes into a large pot and add the sugar and orange juice.
Tie the dried hibiscus in tea bag filters and place them in the pot.
Bring the contents of the pot to a hard rolling boil and occasionally press the tea bags to release some of the hibiscus.
Place a saucer or tablespoon in the freezer.
About 20 minutes in, check to see whether the jam is set. Remove the saucer or spoon from the freezer and place a bit of the hot jam on either of them. Watch whether the jam runs quickly to down the saucer or spoon or whether it is a slow run.
You may also run your hand through the jam(horizontally) to see whether the line closes up or stays. If the line stays the jam is set, if it closes up your jam needs a few more minutes.
If the jam is not set yet, leave to boil further but make sure to check regularly (in 3-5 minute intervals).
Once the jam is ready, pour the hot jam into the glasses, close them with their lids, and turn them upside down for a few seconds. See notes 2.
Turn them the right way up and leave them to cool. Refrigerate them afterward.
Spread on bread or fill your favourite doughnut with this jam.