Delicious blackberry jam made with Pomona pectin.
You can make this with sugar, or an alternative sweetener.
You can also make this with frozen blackberries if you have any in the freezer!
Jar size choices: 125 ml (½ cup / 4 oz) OR quarter-litre (½ US pint / 250 ml / 8 oz)
Processing method: Water bath or steam canning
Yield: 4 x quarter-litre (½ US pint) jars
Headspace: 1 cm (¼ inch)
Processing time: 10 minutes
Blackberry Jam (Pomona)
- Wash and stem blackberries.
- Mash the blackberries a layer at a time in something like a pie plate using something like a potato masher.
- Press through sieve or food mill to remove seeds, if desired (see discussion in Notes below.)
- Measure 1 litre / 4 cups of juice and put juice in large stainless steel pot.
- If using sugar or Splenda, put them in a bowl, add the pectin powder, and mix. If using a liquid sweetener such as honey or liquid stevia, ladle out about 4 tablespoons of juice and put in a small bowl. Add the pectin powder all at once, and stir it into juice. Whichever combination you made up, set it briefly aside.
- Add lemon juice to the pot.
- Add the calcium water to the pot.
- Bring the pot to a boil over high heat.
- Add the pectin mixture a little at a time, stirring constantly.
- Let boil vigorously for another 2 minutes, stirring constantly.
- Remove from heat.
- Ladle into 125 ml (4 oz) or quarter-litre (½ US pint / 8 oz) jars.
- Leave 1 cm (¼ inch) headspace.
- Debubble, adjust headspace.
- Wipe jar rims.
- Put lids on.
- Process in a water bath or steam canner.
- Process either size jars for 10 minutes; increase time as needed for your altitude.
How to water bath process.
How to steam can.
When water-bath canning or steam canning, you must adjust the processing time for your altitude.
Information about Pomona pectin.
More information about Sugar and Salt-Free Canning in general.
- If using frozen blackberries, measure before thawing. Then thaw them either on the counter or in the microwave (zap from frozen for 4 to 5 minutes.) Don’t drain any juice off; mash that back into the berries.
- Mash the fruit by hand for best results. Using a machine will damage the natural pectin in the fruit.
- You don’t have to strain any seeds out at all if you don’t want to. Or, you could strain them out, then add a bit back in for “look.” Some people find some varieties of blackberries too seedy for their seed tolerance level — it will depend on your preferences and the variety of blackberry you have to work with. Obviously straining out seeds will reduce your volume yield somewhat. Straining the seed pomace a second time can yield more juice. If you strain and then end up with less than the full 1 litre / 4 cups of juice to work with, then either juice some more blackberries, or, don’t worry about it and just push on with the recipe still using the indicated amounts of other ingredients and processing time.
- Pomona pectin comes with a small pouch of powdered calcium for you to mix with water to make calcium water.
- The pectin powder will clump if you just mix it straight into the fruit; that’s why you mix it with something first.
Pomona. Blackberry Jam. Accessed June 2020 at https://pomonapectin.com/recipes/blackberry-jam/
Using 1 cup / 200 g sugar as the sweetener.
Per 1 tablespoon: 19 calories
Using Splenda granulated instead of sugar, per tbsp: 9 calories, 2 g carbs, 1 g protein, 1 g saturated fat, 3 mg sodium