Wash the apples and cut off any bruised bits.
Cut the apples into thick chunks without peeling or coring.
Put in a pan with the lemon juice and enough cold water to cover.
Bring to the boil and simmer until the apples are very soft and the liquid is reduced by a third.
Strain the apple mixture through a jelly cloth overnight.
Do not squeeze the apples through as this will make a cloudy jelly.
Measure the strained liquid and for every 450ml of liquid add 450g sugar.
Put the apple liquid, sugar and rosemary into a large pan.
Stir until the sugar has dissolved and then boil rapidly for 10 minutes or until setting point is reached.
To test if the setting point has been reached spoon a little of the jelly onto a chilled sauce, then push the surface of the jelly.
If the surface wrinkles it has reached setting point.
Pot the jelly in warm, clean, sterilised jars, cover with waxed discs until the jelly cools, then cover and seal.
