Finely chop the bell pepper with a knife or food processor, then spread the pieces in paper towels and press out excess moisture before measuring 1 ½ cups loosely, not packed. They should look finely minced, almost like relish, and removing that extra liquid helps the jelly set instead of staying thin.
Finely chop the jalapeños the same way and blot or squeeze out the extra liquid before measuring them for the pot. Wear gloves while handling them, and aim for very even pieces so the heat and texture distribute well through the jelly.
Add the bell pepper, jalapeños, sugar, vinegar, lime juice, and salt to a large deep pot, then bring the mixture to a boil while stirring often. As it heats, the sharp vinegar smell softens and a sweeter pepper aroma starts to come through.
Lower the heat only enough to prevent boil-over and keep the mixture boiling for 10 minutes. A full rolling boil should keep bursting across the surface and continue even when you stir, not collapse into a simmer.
Slowly stir in the liquid pectin and boil for 1 more minute. The syrup will still look fluid at this stage, but the pectin needs that final short boil to activate properly.
Take the pot off the heat and let the jelly rest for 5 minutes, then stir well and ladle it into containers before securing the lids. This short rest lets the syrup thicken slightly so the peppers stay suspended more evenly instead of rushing to the top.
If you like, turn the sealed containers upside down for about 30 minutes, then return them upright and let them cool at room temperature for 24 hours. This optional step can help redistribute the pepper pieces and reduce floating in the finished jars.
For refrigerated or frozen jelly, cool the containers fully and store them as directed for your chosen method. The jelly should look glossy and loose at first, then continue to settle as it cools.
For canned jelly, ladle the hot mixture into sterilized jars, wipe the rims clean, fit washed new lids and rings, and process in a water bath canner for 10 minutes or longer if you are at high altitude. Clean rims matter because sticky residue can interfere with a good seal.