our passion fruit vine overfloweth this time of year so i've been making a bunch of jam. while the pulp is mostly just juice and seeds, the pith inside the shells has a significant amount of pectin, so to make preserves (or jam) we can leverage that without needing to introduce store bought pectin.
amounts here are going to vary depending on how big and juicy your fruit is, but it's not an exact science.
when selecting fruit to use for this recipe, i lean toward smoother fruits for the skins and crinkly fruits for the additional juice/pulp.
we add the juice at the end because it doesn't taste as nice after boiling for quite some time. supposedly. idk.
granulated white sugar
canning jars and fresh lids
large pot and rack for canning
- the night before you want to make the jam, scrub the passionfruits clean, then juice by cutting them in half and scraping out the seeds and pulp into a bowl or resealable container - you'll be adding this in at the end.
- submerge the shells in water in a large cooking pot and soak overnight on the counter.
- the next day, bring the shells and water to a boil and cook for 30 minutes or until the shells are tender. allow to cool, then use a spoon to remove the webbing that the pulp was attached to, then scoop out the pith from the hard purple shell. discard the webbing and hard purple shell.
- place the pith in a blender and note how many cups you have - you'll need the same amount, cup for cup, of sugar. add in some of the cooking water (around 1-2 c for every 5c pith) and blend until smooth. this is your jam base!
- add this mix to a high-walled, thick-bottom cooking pot - larger than you think you'll need. here you'll also add lemon juice - around 1 lemon for every 3 cups, or more to taste. add the sugar. stir to combine and heat over medium-high until it comes to a boil, stirring occasionally to prevent scorching.
- in the meantime, add the reserved pulp to a blender. pulse a couple of times, then strain through a fine-mesh strainer to remove the seeds and solids. you can add some seeds back in if you like, for texture. you'll want about half the volume of your jam base of strained juice - feel free to juice more if you don't have enough.
- this is also a good time to start heating up your canning jars.
- when the jam mixture reaches 220 F on an instant-read thermometer, it's ready. at this point you can also do the spoon test or plate test to confirm that it's set.
- when the jam is ready, lower heat and stir in the reserved juice/pulp, allowing it to just start bubbling again before removing from heat. immediately ladle into your hot canning jars and seal in a hot water bath.