adapted from Foodie with Family, via Cakewalk
makes 3 1/2 pints plus additional syrup
3 pounds firm, fresh jalapeno peppers, washed and sliced about 1/8 inch thick
2 cups apple cider vinegar
6 cups white granulated sugar
Combine cider vinegar and white sugar in a large pot and bring to a boil over high heat. Once the mixture reaches a rolling boil, reduce heat to low and simmer for 5 minutes. Add the pepper slices and simmer for exactly 4 minutes. Using a slotted spoon, transfer the peppers into prepared sterilized canning jars, filling to within 1/4 inch of the upper rim of the jar.
Return the remaining syrup to the stovetop and bring it to a full rolling boil. Boil hard for 6 minutes.
Using a ladle, pour the boiling syrup into the jars over the jalapeno slices. Insert a chopstick (or a small icing spatula) to the bottom of the jar two or three times to release any trapped pockets of air. Adjust the level of the syrup if necessary. Wipe the rims of the jars with a clean, damp cloth and top with new lids and rings to finger-tip tightness.
NOTE: We always can the additional candied jalapeno syrup as well. It makes a great addition to bloody marys, salad dressings, etc.