To make the preserves last longer, sterilize the jars, add the figs, fill with the syrup to within 1-inch from the top. Seal the jars and place them in a hot water bath. Bring to a boil, then lower the heat and simmer for 15 minutes. Turn off the heat and leave the jars in the hot water for 2 minutes. Carefully, remove the jars and place them on a baking sheet. Let them cool for at least 6 hours and then they are ready to be stored.