Explainers

How to make jam

With the final glut of summer stone fruit in grocery stores, now is the perfect time to make jam so you can savour the sweetness year round.

To make jam, you need fruit with a good balance of acid and pectin, such as plums. Plum season starts in early summer and continues through to late autumn, depending on the variety, so now is an ideal time to make a batch of jam.
For this spiced marsala version, we've used dark-skinned, red-fleshed Mariposa plums (also known as blood plums), however, you could also use a yellow-fleshed variety such as President, Narrabeen, or Santa Rosa. The recipe below makes 4½ cups and takes 1 hour, plus cooling.
Use a large, wide pan made from aluminium, enamel or stainless steel. Avoid copper or unsealed cast iron as acids may react with the metal and spoil the flavour. For an airtight seal, ensure jars are free of cracks, properly sterilised and have a tight-fitting lid.
Savoury jam is a great accompaniment to meat, such as duck, ham or pork. To make a savoury version of this jam, in step 4, omit the marsala and stir in ½ cup white or red wine vinegar and add 2 tsp salt, ½ tsp freshly ground black peppercorns and 1 finely chopped long red chilli.

How to make jam, step by step

Step 1 Quarter 1kg blood plums and remove stones. Combine plums, 60ml (¼ cup) orange juice and 250ml (1 cup) water in a large saucepan and bring to the boil. Reduce heat and simmer, uncovered, until plums are pulpy (15 minutes).
Step 1.
Step 2 Meanwhile, place 8 cloves and 1 star anise on a small square of muslin, then tie with kitchen string to secure.
Step 2.
Step 3 Measure fruit mixture and allow 220gm (1 cup) sugar to each cup of fruit mixture. Return fruit mixture, sugar, 125ml (½ cup) sweet marsala, 1 cinnamon quill and muslin bag to pan then stir over high heat, without boiling, until sugar dissolves. Bring to the boil then boil, uncovered, without stirring, until jam gels (35 minutes). To test if the jam has gelled, place a spoonful on a chilled saucer; wait for a minute, then run a finger through the jam; the mixture should wrinkle.
Step 3.
Step 4 Remove and discard cinnamon and muslin bag. Pour hot jam into hot sterilised jars and seal immediately. Label and date jars when cold. Store in a cool dark place for up to 12 months, and refrigerate after opening.