This homemade no-sugar blueberry jam is a summer staple recipe with warming cloves and cinnamon that is naturally sweetened with apple cider. This recipe makes about 6 half pint jars of jam. Recipe is adapted from the book Naturally Sweet Food in Jars by Marisa McClellan.
Prepare your boiling water canner for a water bath method. Put the canning rack at the bottom of a large pot and heat the jars in simmering water until it's time to use them. Wash the lids in warm soapy water and set aside until ready for use.
Make the Blueberry Jam
Mix the calcium water as per Pomona's Pectin instructions.
Rinse the blueberries thoroughly and add them to a non-reactive pan (preferably one that is wide with lower sides). Pound the berries with a potato masher until they are fully crushed.
Add 1 1/2 cups of the apple cider, lemon zest and juice, spices, and calcium water mixture into the pot with the crushed blueberries.
Heat the pot on high until it is at a rolling boil, then lower the heat to medium-high and stir it frequently for about 15-20 minutes.
When the blueberry mash begins to thicken and has reduced by about a quarter, whisk the pectin powder into the remaining 1/2 cup of apple cider, and add it to the pot.
Return the heat to high and bring the mixture to a full rolling boil. Cook for about 1-2 minutes until you see signs of thickening.
Once the jam is beginning to thicken and has finished cooking, remove the pot from the heat. Use a jar lifter to place one jar at a time onto a wooden cutting board or kitchen towel, and ladle the hot jam into the funnel to pour the jam into the prepared jar. Leave about 1/2 inch of headspace, and remove any air bubbles.
Wipe the rim of the jam jar, and center a lid on the jar and apply the band, adjusting to fingertip tight. Place the jar into the boiling water canner, then repeat the process until all of the jars are filled.
Process in a boiling water bath for 10 minutes. Turn off the heat, remove the pot lid, and let the jars sit inside for 5 minutes.
Use a jar lifter to remove the hot jars, and let them cool for 12 to 24 hours. Check to make sure the lids are all sealed, they should not flex when the center is pressed.
Notes
Pomona’s Pectin comes with 2 packets, the smaller one with calcium powder is needed to make the calcium solution with water. The larger packet has pectin powder that is added to the apple cider while making this jam.