Slice jalapeno peppers. You can cut out while white membrane and seeds or leave them in (or you can even do half and half). Membrane and seeds are what contribute to the heat level. I highly recommend that you use gloves when you handle jalapenos!
Smash garlic cloves and set them aside.
In a medium sauce pot, combine water, vinegar, salt, peppercorns, mix and bring it to simmer. Whisk slowly and simmer gently until the salt and sugar are dissolved.
Add sliced jalapenos and smashed garlic to the pot, make sure they are submerged and take off heat.
Let them sit about 15 minutes and transfer the jalapenos (just the jalapenos) into the jars.
Pour the pickling liquid into the jars almost to the top.
Make sure to let them cool completely to room temperature. Close the lid tight and refrigerate.
Notes
Storing: Pickled jalapenos should last a pretty long time in the refrigerator, when stored properly, in an air-tight container with a lid. Make sure to use clean utensils to take some jalapenos out each time. Keep them refrigerated and closed. They should last for several months in the refrigerator.