Sterilising glass jars is crucial in order to safely preserve jams, marmalades, jellies or chutneys.
Buy new jars each time and, once you have used the lids once, buy new lids. Never use the same lids twice.
Inspect your glass jars for scratches, chips or cracks. They must be in pristine condition.
Preheat your oven to 110˚C/90˚C fan/gas mark ¼.
Wash the glass jars and their lids with hot soapy water. While still damp, and without touching the insides of the jars or lids, place them open sides-up on a baking tray lined with a clean tea towel. Place in the oven for 35 minutes.
Remove from the oven and carefully pour your hot jam or chutney into the hot jars. Be careful not to touch the inside of the jars. Close the lids.
Turn the jars upside-down and leave them to cool completely. Store in the fridge for up to three months.
To preserve a jam for longer outside the fridge, fill a large, heavy-bottomed pan with water. Bring to the boil, then fully submerge the glass jars in it, lid side up. Leave them in the boiling water for 10 minutes and then, using tongs, carefully remove. Allow to cool completely, then store in a cool, dark, dry place for up to a year, unopened. Once open, store in the fridge.