Step 1: Wash and prepare your peppers. Remove stems, seeds, and membranes from bell peppers and jalapeños (adjust jalapeño seeds/membranes based on desired heat). Finely mince all peppers using a food processor or by hand. Sterilize half-pint canning jars, lids, and bands; keep them hot.
Step 2: In a large, heavy-bottomed pot or Dutch oven, combine the minced peppers, granulated sugar, and apple cider vinegar. Stir well to mix all ingredients thoroughly.
Step 3: Bring the mixture to a full rolling boil over high heat, stirring constantly to prevent sticking and ensure sugar dissolves completely. A 'rolling boil' is one that cannot be stirred down.
Step 4: Once a rolling boil is achieved, immediately add the liquid fruit pectin. Stir vigorously for 1 full minute, maintaining the rolling boil the entire time. This ensures the pectin activates properly.
Step 5: Carefully remove the pot from the heat. Skim off any foam that has formed on the surface of the jelly using a large spoon. Promptly ladle the hot pepper jelly into your hot, sterilized jars, leaving 1/4 inch of headspace from the rim.
Step 6: Wipe the rims of the filled jars clean with a damp cloth to ensure a good seal. Center the hot lids on the jars and screw on the bands until they are finger-tight.
Step 7: For long-term storage, process the jars in a boiling water canner for 10 minutes. Ensure jars are fully submerged. After 10 minutes, turn off heat, remove canner lid, and let jars sit for 5 minutes before carefully removing to a wire rack. Allow to cool undisturbed for 12-24 hours.
Step 8: After cooling, check seals by pressing on the center of each lid. If it doesn't flex, it's sealed. Label and store sealed jars in a cool, dark place for up to 1 year. Refrigerate unsealed jars or once opened, and consume within 3-4 weeks.