5 cups blueberries (halved and crushed)
1 cup water
1 box Certo pectin crystals
2 & 1/2 cups sugar
Bring the blueberries, water, pectin and 1 cup of sugar to a boil with high heat in a large pot.
Add the rest of the sugar.
Bring to a hard boil for 1 minute.
Remove from heat.
Stir and skim foam for 5 minutes.
Pour into sterilized jars