Measure all ingredients for the brine- vinegar, water, sugar and salt and add to a saucepan to simmer.
Fill the water bath canner with enough water that will cover the jars about 1-2" and begin heating the water for processing.
Wearing latex gloves, cut the jalapeno peppers into thin slices on a cutting board. TIP: removing seeds will help reduce heat. Mince garlic cloves- one for each jar. You can add the minced garlic in the bottom of the jar or the top--either way.
Pack sliced peppers into jars, leaving 1/4-1/2" head space.
Pour brine over peppers covering them- with 1/4-1/2" headspace.
Using the canning tool or a non metallic spatula, insert into the jar to remove air bubbles.
Wipe the rims of jars with a clean damp towel to remove any brine, or garlic that would prevent it from sealing.
Add lids and rings to the jars. Be careful not to add rings too tightly.
With jar lifter, add jars to the water bath canner making sure that water is covering the lids --1-2". Cover the canner with the lid.
When water begins to boil, begin timing processing for 10 minutes.
When processing has ended, remove the canner lid and leave in the canner for about 5 minutes before using the lifter to set them on a clean towel in a draft free spot to cool and seal.
Make sure that all the lids have "pinged" and don't move them for 24 hours to ensure sealing.
Before moving them to storage, make sure the lids are "indented" and have sealed, label with the name and date, and remove rings.