Place cranberries into a large stockpot. Add port and water. Bring to a boil on medium heat, stirring occasionally.

Reduce heat to medium-low. Cover and simmer for 15 minutes, stirring occasionally.

Remove from heat and pour into jelly bag (or cheesecloth) and allow juice to drain through into a bowl. (for clear jelly do not squeeze)

Measure 6 cups of prepared juice into a large saucepan. Add sugar and stir. Bring to full rolling boil over high heat, stirring constantly. Boil for 1 minute.

Remove from heat and immediately stir in pectin. Stir and skim foam for 5 minutes.

Pour into warm, sterilized jars and seal. Let stand at room temperature until set. Makes about 8 cups jelly.