In a large saucepan combine blueberries, sugar, lemon zest and juice, vanilla bean paste, and water. Cook over medium/high heat bringing the mixture to a boil for about 5-7 minutes or so. At this point there should be a decent amount of liquid coming from the blueberries. Reduce the heat to low and continue cooking over low heat stirring every few minutes or so to ensure the mixture does not stick to the pot.
Cook until the liquid has reduced, thickened, and blueberries are very soft. This will take anywhere from 45-50 minutes. Remove from heat and allow to cool for about 10 or 15 minutes or so. The jam will thicken as it cools. At this point you can either blend it until smooth or leave as is. I like my jam chunky, so I leave as is.
Ladle the jam into mason jars. Seal the jars and allow the jam to come to room temperature before placing them in the refrigerator.
Jam will last about 3-4 weeks. Sometimes even more.
Makes about 16 ounces of jam.