Prepare your canning jars, lids, and rings. If canning, ensure your water bath canner is filled with water and heating.
In a large, heavy-bottomed pot, combine the chopped strawberries and cranberries.
Cook over medium heat, stirring occasionally, until the berries soften and release their juices, about 10-15 minutes. Mash the berries with a potato masher or the back of a spoon to your desired consistency.
Stir in the granulated sugar, lemon juice, cinnamon, allspice, and cloves.
Bring the mixture to a rolling boil, stirring constantly.
Continue to boil, stirring frequently, until the jam reaches the setting point. This can be tested by dropping a small amount of jam onto a chilled plate; it should wrinkle when pushed. This may take 20-30 minutes.
If canning, stir in the calcium chloride solution (if using) and boil for 1 minute more.
Remove the pot from the heat. Skim off any foam from the surface.
Ladle the hot jam into prepared jars, leaving 1/4 inch headspace. Remove air bubbles. Wipe rims clean.
Place lids on jars and screw on rings until fingertip tight.
Process the jars in a boiling water bath canner for 10 minutes (adjust for altitude if necessary).
Remove jars from the canner and let them cool completely on a wire rack. Check seals after 12-24 hours.
Notes
For a smoother jam, you can pulse the berries in a food processor before cooking.
If you are not canning, store the jam in the refrigerator for up to 3 weeks.
This jam makes a wonderful edible present for friends and family.
Consider pairing with a meal planning service for easy holiday meal preparation.