In a medium pan, add the blackberries and heat over medium-high heat. Stir occasionally with a wooden spatula. After 5-10 minutes, the blackberries will start to break down into a puree. If needed, use the spatula to help them along.

If you prefer a smoother jam, use a hand blender to blend the mixture. Then, strain the mixture through a fine-mesh sieve to remove the seeds. For a chunkier jam, skip this step.

Return the blackberry puree to the pot and stir in the lime or lemon juice and zest (if using). Cook for a few more minutes to combine the flavors.

Add the Allulose or Erythritol, stevia powder, and Inulin. Stir well to combine. Lower the heat to medium-low and cook for about 10 minutes, allowing the mixture to thicken slightly. Taste the jam and adjust sweetness with additional stevia liquid or powder if desired.

If using liquid pectin, remove the pot from heat and stir it in. Test the set by placing 1/2 tsp of the jam on a cold plate; if it doesn’t set, bring the mixture to a boil again for 1-2 minutes and test again. If using gelatin, dissolve the gelatin powder in 1-2 tbsp of hot water, then stir it into the jam until fully dissolved and smooth.

Transfer the jam to a heat-proof jar with a lid. Let it cool completely to room temperature, then refrigerate for at least 2 hours (3 hours or overnight if using gelatin) to set. Enjoy your jam over toast, crackers, oatmeal, or your favorite dishes!