Fresh or frozen cranberries can be used but allow a few minutes more cooking time if using from frozen.Place all the ingredients into a saucepan, bring to a boil and stir often.Upon reaching boiling point, turn the heat down and gently simmer for 15-20 minutes.Turn off the heat when the cranberries have burst and formed a thick sauce, remove the sprigs of rosemary and allow to cool.Spoon cranberry sauce into sterile jars, refrigerate and use as an accompaniment with roast meat.