I found these instructions from Leite's Culinaria: Hot Food, Dry Wit that seem very close to my process.
- 4 pounds fruit,rinsed and cubed
- 2 C organic granulated sugar
- 1-1/2 C liquid (wine, water, or a mixture of both)
- 1 lemon, halved and juiced
- lemon zest
1. Sterilize the jars for canning by boiling them and their lids.
2. To make the jam, place the fruit, sugar, liquid, and lemon juice,into a large pot and bring to a boil over medium-high heat. Continue to cook, stirring the jam constantly, for about 15 minutes.
3. Reduce the heat to medium. Hold the jam at a constant simmer, checking frequently to make sure the jam isn’t scorched at the bottom of the pot. After 15 minutes, check to see if your jam has set by running a wooden spoon down the middle of your jam. If the jam leaves a path, it's set. If the liquid runs back to fill the path, cook it a little bit longer.
4. Place the jam in sterilized jars, leaving about a 1/2" gap to the top. Gently tap the bottom of each jar on the counter to release any air bubbles. Using a damp clean towel, wipe the rims of the jars and secure the lids and rings. Process in a water bath for 10-15 minutes. Remove the containers with tongs and let cool on the counter.
You’ll hear the sound of can tops popping shortly—a sign that a secure seal has been made. Pop, pop, pop. Or, you can refrigerate the jar without processing and use it within three weeks. Enjoy!