Step 1: Sterilize your canning jars and lids. Wash jars in hot soapy water, rinse, and place in a boiling water canner. Cover with water and boil for 10 minutes. Keep hot until ready to fill. Place lids in a small saucepan with simmering water.
Step 2: In a large, heavy-bottomed pot or Dutch oven, combine the finely chopped bell peppers, jalapeños, apple cider vinegar, and granulated sugar. Stir well.
Step 3: Bring the mixture to a full, rolling boil over high heat, stirring constantly to prevent scorching. Boil hard for exactly 1 minute.
Step 4: Remove the pot from the heat. Immediately add the liquid fruit pectin, stirring vigorously for 1 minute until fully incorporated.
Step 5: Return the pot to high heat and bring it back to a full, rolling boil. Boil hard for another 1 minute, stirring constantly.
Step 6: Test for a set: Spoon a small amount of hot jelly onto a cold plate (previously chilled in the freezer). Return to the freezer for 1-2 minutes. If the jelly wrinkles when pushed with a finger, it’s ready. If not, boil for another minute and retest.
Step 7: Carefully ladle the hot pepper jelly into the sterilized hot jars, leaving 1/4 inch headspace. Wipe the jar rims clean with a damp cloth, center the lids, and screw on the bands until fingertip tight.
Step 8: Place the filled jars into the boiling water canner, ensuring they are covered by at least 1 inch of water. Bring to a rolling boil and process for 10 minutes (adjust for altitude if necessary).
Step 9: Turn off the heat, remove the canner lid, and let the jars sit in the hot water for 5 minutes. Carefully remove the jars and place them on a clean towel on your countertop to cool completely for 12-24 hours without disturbing them. Check seals by pressing on the lid; if it doesn’t flex, it’s sealed. Store in a cool, dark place.