• Place the halved apricots, and the pitted sour cherries if using them, in a jam pan. Add the sugar, lemon juice, and mix well. Cover with a cheesecloth. Macerate overnight at room temperature.
• The next day, bring the mixture to a boil over medium-high heat, stirring occasionally. Cook for 3 minutes, skimming off the foam, then turn the heat off.
• Using a slotted spoon, transfer the fruit to a colander fitted over a large bowl. Let rest for one hour.
• Transfer the liquid drained from the apricots to the jam pan. Bring the liquid to a boil over medium-high heat. Lower the heat to medium and continue cooking until the liquid thickens, stirring occasionally to prevent jam sticking to the bottom. See the post above on how to gauge when the jam is thick enough. If you want to expedite this part of the process, you can start cooking at medium-high heat, then drop to medium heat when you start feeling some sticking when you stir the liquid in the pan with a wooden spatula.
• Next, add the strained fruit and gently mix it with the thickened liquid in the jam pan. Bring to a boil and cook briefly for a few minutes until the jam passes the thickness test. You can test it with a cold saucer or do the 'trail test' I described in the post above.
• Transfer the jam into clean jars, close with tight lids, let cool, and refrigerate for up to 3 months.

Canning apricot jam

• Sterilize mason jars and the lids with bands.
• Fill the hot jars with the hot jam using a clean ladle and a canning funnel, leaving a 1/2" headspace.
• Wipe the rims of the jars, put on the lids and the bands. Tighten the bands finger-tight.
• Process in a water bath canner for 10 minutes (assuming 0 - 1,000 feet above sea level), making sure there is at least an inch of water above the lids. Turn the heat off and let the jars sit in the water for another 5 minutes.
• Remove the jars from the canner and let them cool down. Check the seals, then move to a dry, cool and dark place for storage. This apricot jam, if properly sealed, will have a long shelf life, up to 2-3 years before you will notice a loss of taste quality.