Fig jam is one of the simplest preserves to make and one of the easiest to make badly. The ingredients are figs, sugar and an acid, usually lemon juice. Everything else is technique.
Harvest and sort
Jam starts on the tree. Fully ripe, even slightly overripe figs have the most sugar and flavour. Sort out anything mouldy or sour-smelling; one fermented fig can taint a batch.
Wash and prepare
Rinse briefly, trim the hard tip of the stem, and cut. Halves or quarters give a chunky preserve; a rough chop gives a smoother jam. We leave skins on: they hold colour and a little tartness.
Sugar
Sugar does three jobs: it sweetens, it helps the jam set by binding water, and it preserves by making water unavailable to microbes. Reducing sugar changes all three. See Sugar.
Acid
Figs are a low-acid fruit. Lemon juice brightens the flavour, helps pectin set, and, in tested canning recipes, is what makes the jam safe to process in a boiling-water bath. This is not optional in a canned jam. See Acidity and Food safety.
Cook
A wide, heavy pan and steady, brisk heat. The fruit releases its juice, the mixture boils, foam rises and subsides, and the jam thickens as water evaporates. Fig jam tends to catch on the bottom late in cooking, so stir more as it thickens.
Test the set
Fig jam sets softly. A spoonful chilled on a cold plate should wrinkle when pushed, or a thermometer should read the setting point for your altitude. See Testing the set.
Jar
Hot jam goes into hot, clean jars, leaving the headspace the recipe specifies. Lids on, then either refrigerate for short-term keeping or process in a boiling-water canner according to a tested recipe.
Preserve and enjoy
A processed, sealed jar keeps in a cool, dark cupboard; an unprocessed jar lives in the refrigerator. Either way, once opened, keep it cold and use it within a few weeks. See Storage.
This page describes our own practice. For process times and safety-critical details, follow a tested recipe from the sources listed on the food-safety page.