Step 1

Before you begin, prepare calcium water.To do this, combine ½ teaspoon calcium powder (in the small packet in your box of Pomona’s pectin) with ½ cup water in a small, clear jar with a lid. Shake well.Extra calcium water should be stored in the refrigerator for future use.

Step 2

Wash jars, lids, and bands. Place jars in canner, fill canner 2/3 full with water, bring to a boil. Turn off heat, cover, and keep jars in hot canner water until ready to use. Place lids in water in a small sauce pan; cover and heat to a low boil. Turn off heat and keep lids in hot water until ready to use.

Step 3

Measure mashed blackberries into sauce pan.

Step 4

Add calcium water, port wine, and lemon juice, and mix well.

Step 5

Measure sugar into a bowl. Thoroughly mix pectin powder into sugar. Set aside.

Step 6

Bring fruit mixture to a full boil. Add pectin-sugar mixture, stirring vigorously for 1 to 2 minutes to dissolve the pectin while the jam comes back up to a boil. Once the jam returns to a full boil, remove it from the heat. Taste the mixture to see if you need to add more sugar. This will depend on how sweet or tart your blackberries are. If adding more sugar, turn the heat back on, stir well while mixture returns to a full boil, then remove from heat. Add cinnamon now if desired to help boost the flavors.

Step 7

Fill hot jars to ¼” of top. Wipe rims clean. Screw on 2-piece lids. Put filled jars in boiling water to cover. Boil 10 minutes (add 1 minute more for every 1,000 ft. above sea level). Remove from water. Let jars cool. Check seals; lids should be sucked down. Eat within 1 year. Lasts 3 weeks once opened.