The day before you wish to make the jam, hull and halve 1kg strawberries, leaving little ones whole. Discard any berries with bruises or that are overripe and remove any soft spots. Mix with 500g of caster sugar to coat and place, covered in the fridge overnight.
Before making the jam, place a saucer in the freezer to chill as you need this to test the setting point of the jam.
Sterilise your jars by first washing in hot soapy water then leave to drip dry upside down on a rack in the oven set to 140C/120C fan/gas mark 1. Leave for at least 30 minutes.
Pour the strawberries and any sugary juices into a very large pan or preserving pan, remembering the mixture will rise as it bubbles so be careful!
Add another 500g of sugar, I added some rose petal sugar to this measure for a floral note, along with the juice of half a lemon. Stir over a gentle heat until the sugar has completely dissolved. Bring up to a boil and boil hard until the jam reaches setting point.
Check the setting point every 10 minutes.
To test the setting point;remove the pan from the heat. Take your saucer from the freezer and place a drop of jam onto the cold plate. After a few seconds, push the jam with your finger. If the surface wrinkles it has reached setting point and is ready. If it slides still as a liquid, return to the hob and boil for a further 10 minutes before testing again.
When the setting point is achieved, remove from the heat and stir through a small knob of butter the skim off any scum from the surface of the jam with a large spoon.
Leave the jam to cool and thicken for 10 minutes, this will prevent the strawberries from all sinking to the bottom of the jars.
Carefully remove your sterilised jars from the oven wearing oven gloves, avoiding touching the insides. Stir the jam and laddle into the prepared jars, cover the tops with waxed paper discs (cut to size to cover the entire surface of the jam), press the discs down to create a complete seal. Cover with lids whilst still hot then label and store in a cool cupboard for up to a year. Divine!
Remember: homemade jam is that extra special ingredient that makes everything taste that much better, from morning toast to generous Victoria sponge and simple stunning on a home baked scone!