In a large saucepan, combine the figs, sugar, and lemon juice and zest. Bring to a simmer over medium low heat, stirring constantly.
Cover and simmer over low heat for 1 hour, stirring occasionally. Remove the cover and continue simmering, stirring frequently, until the mixture thickens.
When the mixture gets quite thick, begin to stir constantly to keep from scorching.
While figs are cooking, prepare the jars and lids. Fill the jars with the hot fig jam mixture, leaving 1/4-inch headspace.
Wipe jar rims and threads with a wet paper towel. Add hot lids and rings. Process in water bath at a full boil 10 minutes.
Makes 4 half-pint jars.