Cowberry jam with rosemary

Put the cowberries and water in a pan to cook. Add the rosemary twigs. Simmer over low heat for about 10 minutes. Add the sugar, stir until the sugar has melted and cook for 10 more minutes. Allow to cool for a bit. Sterilise the jars, keeping them in the oven at 100 °C for 10 minutes and place the lids into boiling water for 5 minutes. Pour the hot jam into the jars and seal the jars immediately.