Here is a picture of my jars sterilizing in the water bath canner and my lids sterilizing in a pot of hot water
Here we are filling the jars. The color is beautiful. I cannot say enough about how important a wide-mouth funnel is for making jam.
And now, for the recipe:
Plum Cardamom Jam
4 lbs ripe black plums, pitted and diced
2 cups sugar
3 T strained fresh lemon juice
1 T freshly ground cardamom seeds (or a little more if using pre-ground)
Prepare your water bath canner and sterilize jars and lids
Put the plums and sugar in a wide, 6-8 quart pot. Bring to a simmer, stirring frequently, then continue to cook for 5 minutes. Pour into a colander set over a large bowl and stir the plums gently to drain off the juice. Return the juice to the pan and bring to a boil over high heat. Boil, stirring occasionally, until the syrup is reduced and thick, about 10 minutes.
Return the plums and any accumulated juice to the pan, along with the lime juice and cardamom, and bring to a simmer. Simmer, stirring frequently, until a small dab of the jam spooned onto the cold plate and set in the freezer for a minute becomes some-what firm (it will not gel), about 15 minutes. Remove from the heat.
Ladle the hot jam into the jars, leaving 1/4" headspace at the top. Use a damp paper towel to wipe the rims of the jars, then put a flat lid and ring on each jar, adjusting the ring so that it's just finger tight. Return the jars to the water bath canner making sure there is an inch of water over the jars. Process in boiling water for 5 minutes.