Blackberry Jam With Port - cooking recipe

Ingredients

5 pints blackberries, washed & picked over
1/4 cup fresh lemon juice
6 cups sugar
2 1/2 teaspoons calcium water (comes with pomona's pectin)
2 1/2 teaspoons pomona's universal pectin
1/2 cup good port wine

Preparation

Put the blackberries in a blender and blend until they are pureed. You may need to do this in two batches depending on the size of your blender.
Strain the blackberry puree through a mesh strainer to remove the seeds - stir and press on the puree while it is in the strainer, you want to get as much puree as you can.
Directions for making with Pomona's Pectin:
Measure out 5 cups of the seedless blackberry puree into a preserving pan.
Add the lemon juice and the calcium water and bring to a boil.
Mix the 2 and 1/2 teaspoons of Pomona's Pectin into 2 cups of the sugar. Add to the boiling fruit mixture and stir well for 2 minutes, keeping the fruit at a low boil.
Add the remaining 4 cups of sugar and the port and stir well until the sugar is dissolved. Return to the boil and remove from the heat.
Place into prepared jars,leaving 1/4 inch headspace and process in a boiling water bath for 10 minutes.
Directions for making with regular pectin:
Measure out 5 cups of the seedless blackberry puree into a preserving pan.
Add the lemon juice and the pectin and stir to combine well.
bring to a boil over high heat, stirring all the while.
Add the sugar to the fruit mixture (REMEMBER - you will need a total of 7 cups of sugar if you are making this with regular pectin! Otherwise it may not set) and stir well. Return to a hard boil, stirring constantly.
Add the port and continue boiling & stirring for 1 minute.
Remove from the heat and place into prepared jars,leaving 1/4 inch headspace and process in a boiling water bath for 10 minutes.