Directions

1. In a large saucepan, add blackberry juice and sugar. Mix well. Bring to a boil and skim off any foam. (This will make a thin syrup. To make slightly thicker, add 2 oz pectin (optional) to syrup once cooled.
2. Ladle sauce into canning jars, leaving 1 inch from the top. Make sure rims are clean. If necessary, clean with a damp cloth.
3. Place lids on jars and close tight.

4. Place rack in bottom of pressure cooker. Place jars on the rack. Pour hot water over jars and into inner pot until water reaches ¼ of way up the sides of jars.

5. Set pressure cooker to "canning", adjust time to 10 minutes, and press "start/stop".
6. When done, natural release for 20 minutes, then do a quick release to make sure all pressure is released before opening lid.
7. Open. Using canning tongs, carefully remove hot jars and place on a heat-resistant surface. Allow to cool to room temperature.
8. When jars have completely cooled, remove the screw bands. Lids should be tightly sealed to the jar, and when pressed in the center, they should NOT have any "give" or springing motion. If they do, reprocess immediately.