Blackberry Jam is a low-sugar cooked jam made with Pomona’s Universal Pectin. Pomona’s Pectin contains no sugar or preservatives and jells reliably with low amounts of any sweetener. This recipe was developed by Allison Carroll Duffy. She says: “The rosemary flavor is subtle but present, nicely balancing the sweetness of the berries and giving the jam a little more depth. In making this recipe, be sure to mince the fresh rosemary very, very finely so that the rosemary flavor spreads evenly throughout the jam, and so that you avoid having any noticeable pieces of rosemary in the jam, as they are not particularly appealing to bite into. Additionally, for reasons of canning safety, be sure to use the amount of lemon juice indicated in the recipe, and do not increase the quantity of rosemary, as it can impact the pH of the final product.” Feel free to use other sweeteners that measure like sugar or honey in this recipe.
If you’re not sure if your jam is sweet enough, taste it after the pectin is dissolved and jam has come back up to a boil. Not sweet enough? Add more sweetener and stir 1 minute at full boil.
Servings 5 cups
- 2¼ pounds sweet blackberries this is approximately 8 cups of whole berries
- 2¼ teaspoons fresh rosemary finely chopped
- ¼ cup lemon juice bottled
- 2 teaspoons calcium water see step #1
- 1¼ cup sugar
- 2 teaspoons Pomona’s Pectin mixed with sweetener
- 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.
- Wash and rinse jars, lids, and screw bands. Set screw bands aside until ready to use. Place jars in boiling water bath canner with a rack, fill at least 2/3 of the way full with water, and bring to a boil. Boil jars for 10 minutes to sterilize (add 1 additional minute of sterilizing time for every 1000 feet above sea level), then turn down the heat and let jars stand in hot water until ready to use. Place lids in water in a small pan, bring to a low simmer, and hold there until ready to use.
- Rinse the blackberries, then place them in a mixing bowl and mash them. (A potato masher works well for this.).
- Measure out 4 cups of the mashed berries. (If you have any left over, you can use it for something else). Pour the measured mashed berries into a large saucepan. Add finely chopped rosemary, lemon juice, and calcium water, then stir to combine.
- In a separate bowl, combine the sugar and pectin powder. Mix well and set aside.
- Bring the berry mixture up to a rolling boil over high heat. Add the sugar-pectin mixture, then stir vigorously for 1 to 2 minutes, still over the highest heat, to dissolve pectin. Return jelly to a boil, then remove from heat.
- Remove hot jars from canner and fill jars with jam, leaving ¼ inch of headspace. Remove trapped air bubbles, wipe rims with a damp cloth, and put on the lids and screw bands, tightening bands only to “fingertip tight” (until resistance is met, and then just the tiniest bit more).
- Place jars in the hot water, on the rack inside the canner. (Make sure jars are upright, not touching each other or the sides of the canner, and are covered with at least 1-2 inches of water). Place the lid on the canner, return the canner to a rolling boil, and boil for 10 minutes. (Add 1 minute additional processing time for every 1000 feet above sea level.)
- Turn off heat and allow canner and jars to sit for 5 minutes. Then, remove jars from canner.
- Allow jars to cool undisturbed for 12-24 hours. Then, confirm that jars have sealed. Remove screw bands from sealed jars, rinse off outside of jars if necessary, label jars, and store for later use.