Note: Jalapeno sizes can vary. Cathy always uses at least 30 jalapenos, increasing the amount if they are small.
1. Have ready 10 (8-oz.) jelly jars and two-part lids (seal and screw-on band). Fill a large stockpot with water and bring to a boil over high heat. Keep at a simmer while you prepare the jelly.
2. Wearing rubber gloves, remove stems and cut jalapenos in half lengthwise. Remove and discard seeds; if you want more heat, keep some of the seeds. Thinly slice halves by hand or in a food processor using the slicing disk.
3. Place jalapenos, sugar, and vinegar in a 5-quart Dutch oven or stockpot. Over high heat, bring to a boil and continue to boil for 6 minutes. Add pectin, stir well, and boil for an additional 3 minutes, stirring frequently.
4. Immediately pour jelly into prepared jars. To seal jars, wipe rim if necessary, press on lid, and screw on band. (If there's any extra jelly, you can enjoy it right away.) Work quickly but carefully - jelly will be very hot. Place jars in simmering water and raise heat to bring water to a boil. Boil jars for 5 minutes, then remove and allow to cool to room temperature, about 2 hours. You should hear the jar pop as you remove it, an indication that it's sealed; once cool, the lids should be smooth and flat. Store for up to a year in a cool, dark area out of direct sunlight.
Source: Hannaford fresh Magazine, July - August 2008