Ingredients
Equipment
Method
- Use a chef's knife and cutting board to dice the watermelon flesh into small, uniform chunks. Transfer the cubes to a blender or food processor and pureé until completely smooth, with no large pieces remaining.
- Pour the watermelon pureé into a heavy-bottomed saucepan over medium heat. Bring to a gentle simmer, stirring occasionally, and cook for about 5 minutes until the mixture is heated through and begins to thicken slightly.
- Add the granulated sugar to the saucepan and stir until fully dissolved. Increase heat to bring the mixture to a gentle boil, maintaining constant stirring. Continue boiling, stirring frequently, until the mixture thickens and reaches a temperature of 220°F (104°C) on a candy or jam thermometer, approximately 15-20 minutes. You will notice the jam becoming more translucent and glossy.4 cups watermelon flesh, cubed
- Remove the saucepan from heat and stir in the lemon juice to brighten the flavor and help with setting. Use a spoon to test the jam's consistency on a chilled plate; it should gel slightly and hold its shape after a few seconds.4 cups watermelon flesh, cubed
- Pour the hot jam into sterilized jars, leaving about 1/4 inch of headspace at the top. Wipe the rims clean with a damp cloth and seal with lids. Process in a boiling water bath for 10 minutes to ensure proper sealing and preservation.
- Let the jars cool completely at room temperature. Once cooled, check seals by pressing the center of each lid; they should be firm and not pop back. Store in a cool, dark place. The jam is ready to spread on toast or use as a fruity topping.
Notes
Ensure all jars are sterilized before filling to maximize shelf life. The jam can be stored refrigerated for up to 3 weeks or canned for longer preservation.