I make the jam the afternoon or late evening the day before. Next day I run the dishwasher with the jars, lids and all on the rinsing cycle (I do this so the jars will be steralised and heated) and when they are dry and still very warm I full them. Make sure the jars and lids are thoroughly dry. The jam is usually cool or sometimes slightly warm. I never seal the jars while they are still warm, otherwise the lids can perspire and cause mould to grow. I wait for everything to cool, then seal. Then I place them in a hot water bath for two to three minutes, remove and wipe dry and store in cool pantry. They last a very, very long time and always taste freshly made. I use fruit pectin in my jams and marmalade.