Damson and Rosemary Jelly

In a large pan, add the water and the plums. Do not stone or chop the plums, but allow them to burst naturally whilst cooking. Bring to the boil, then simmer until the fruit is soft. Take a large clean bowl, and lay in it a large piece of muslin. Spoon the plum mixture into the muslin and lift u so that it forms a bag, with the juices running into the bowl. Strain the mixture through the muslin. The easiest way to do this is to let the mixture cool until it can just be touched. Life the bag over the bowl and twist it continuously so that the mixture is squeezed. For each 600ml of juice that you get in the bowl, add 450g sugar and 1 tbsp lemon juice. Pour back into the pan and heat until the sugar has dissolved. Raise the heat and boil rapidly until the setting point is reached. To find this point, test the jelly every 10 minutes by dipping a spoon in (don’t take out a spoonful, just let it coat in the mixture). When the spoon is withdrawn from the heat, the film of jelly should wrinkle to the touch. Place a 1-2 inch long sprig of fresh rosemary in the bottom of each jar and pour over the mixture. Seal down immediately. Leave 1-2 days before eating, to allow the rosemary flavours to infuse into the jelly.