Immerse 5 (8-ounce) jars in simmering water until jam is ready, or at least 10 minutes. Wash lids and rings in warm soapy water.
Combine 1/2 cup of water and 1/2 teaspoon calcium powder in a small jar with a lid to make calcium water. (Note: you will use just 2 teaspoons calcium water for 4 cups mashed fruit. Store the remainder in the refrigerator and use within 6 months.)
Mix pectin powder and sugar in a bowl. Place mashed berries, 2 teaspoons calcium water, lemon juice, and habanero pepper in a medium-sized pot and bring to a boil over medium-high heat. Once berry mixture is boiling, add sugar mixture and stir vigorously for two minutes. Bring back to a boil and remove from heat.
Ladle jam into hot, sterilized jars, filling to within 1/4 inch of the top. Run a clean knife or thin spatula around the insides of the jars after they have been filled to remove any air bubbles. Wipe the rims of the jars with a moist paper towel to remove any food residue. Top with lids and screw on rings.
Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil and lower jars 2 inches apart into the boiling water using a holder. Pour in more boiling water to cover jars by at least 1 inch. Bring the water to a rolling boil, cover the pot, and process for 10 minutes.
Remove the jars from the stockpot and place onto a cloth-covered or wood surface, several inches apart, until cool. Press the top of each lid with a finger, ensuring that the seal is tight (lid does not move up or down at all). Store in a cool, dark area.
