Jars for Chilli Jam

Our answer

Mason jars are normally used for canning and come with a 2-part lid. Once the jars and the flat part of the lid system (called the seal) have been sterilized the jars are fulled with produce and the seals put on top of the jars. The rings are then screwed over and the jars are processed in pans of boiling water for specified times. As the jars cool a vacuum forms in the jar and this helps to preserve the produce.

Unfortunately we have not used this system for Nigella's Chilli Jam (from Christmas and on the Nigella website) so we don't have our own guidelines but Ball's own website (www.freshpreserving.com) have guidelines for how to can jam once it has been made and these guidelines look as if they may be appropriate for the Chilli Jam. We would suggest making the Chilli Jam in single recipe quantities and making large scale quantities of jam can be problematic with domestic equipment.

The other alternative would be to use the old-fashioned wax seal and cellophane lid. Wax seals, cellophane circles and elastic bands are available from suppliers such as Lakeland in the UK. Make sure that the wax paper discs fit snugly inside the neck of the jar (you may need to trim them down to fit). Once the hot jam has been put into the sterilized jars then a circle of wax paper is pressed on to the surface of the jam (wax side down), forming a seal. You can then screw on the seal and ring of the lid system (a vacuum should form as the jam cools). Alternatively let the jars cool and put a cellophane cover over the top of the jar. You could then loosely screw on the seal and ring system over the cellophane.