To begin, cook the blackberries and water together in a skillet for 10 minutes. (I use a cast iron skillet.)
Once the berries have softened, take a potato masher and smash the berries. If you don’t have a potato masher, you could carefully use the back of a wooden spoon. Carefully, because the berries might squirt juice and blackberry juice stains!
As you mash the berries, if you see any of the hard berry cores, remove them. Occasionally, when a berry is picked, the hard core comes off of the stem and stays inside the berry.
Add in the gelatin, lemon juice, and honey.
Note: I generally will use a third of a cup for a batch of jam. However if your berries are tart, you may need an extra tablespoon or so. Taste a berry before you start the jam, so you’ll know if you will need that extra bit of honey.
Cook and whisk this over medium heat to dissolve the gelatin. Let it all cook together for about 10 minutes.
Once the jam has cooked, spoon it into a jar. Allow the jam to cool to room temperature, then close the lid on your jar and refrigerate 6 hours or overnight.