Prepare canning equipment by sterilizing jars/lids, and filling canner 2/3 full of hot water to keep hot
Combine apple cider vinegar, sugar, and spices in a 4+ quart pot
Stir together, and heat over medium heat to a simmer. Continue simmering for 5 minutes
While brine is heating, slice jalapeños thinly – anywhere from 1/16 of and inch, to 1/6 of an inch thick, depending on your preference, and discard stems
When brine is ready, stir sliced jalapeños, and heat back up to simmering
Simmer another 3-5 minutes, until jalapeños are a dull green color
Remove from heat, and ladle into jars, leaving about 1/2 inch of headspace in jars. Make sure each jars gets enough brine to cover, or mostly cover, jalapeños
Wipe rims with a soft cloth to remove any debris, and screw down lids and rings
Place in canner, making sure the water in the canner submerges jars by at least an inch
Bring canner to a full rolling boil, and process half pints for 10 minutes, or pints for 12 minutes
After processing time, remove from heat and let cool 30+ minutes
Remove jars from canner, and cover with a towel to finish cooling
After 24 hours, you may test seals, and store in a cool place out of direct light