For each of these recipes for curd or jam, sterilise two standard (450g) jam jars by putting them through the dishwasher on a hot wash or rinsing them in hot water, then placing them in a preheated oven at 180°C (gas 4) for 15 minutes. (I stand them, open side up, spaced so they aren’t touching, on a baking sheet lined with a tea towel or newspaper). Use new lids each time you make jam. If you haven’t got new lids, then have cellophane discs ready for the tops of the jars (as well as the wax discs).