Start by donning a pair of gloves to protect your skin from the jalapeno oils. Rinse 1 pound of fresh jalapenos under cold water, then pat them dry. Slice the peppers into 1/4-inch rings, removing the stems. Pack these colorful slices tightly into sterilized jars, leaving a 1/2-inch headspace to allow for brine coverage and expansion during processing.

In a medium saucepan, combine 2 cups of white vinegar, 1 cup of water, 2 tablespoons of kosher salt, and 2 tablespoons of granulated sugar. Add 4 smashed garlic cloves, 1 teaspoon of black peppercorns, and 1 teaspoon of dried oregano to the mix. Heat the mixture over medium-high until boiling, stirring occasionally until the salt and sugar dissolve. Once boiling, reduce the heat and simmer for 5 minutes to allow the flavors to meld.

Carefully pour the hot pickling brine over the jalapeno slices in the jars, ensuring they are completely submerged. Use a clean spoon or butter knife to remove any air bubbles that may have formed. Wipe the rims of the jars with a clean cloth to ensure a proper seal, and then place the lids on, tightening the rings just until they’re fingertip tight to secure the jars.

For long-term storage, place the jars in a large pot of boiling water, ensuring they're covered by at least an inch of water. Process the jars in the water bath for 10 minutes. This step helps to preserve your pickled jalapenos and enhances the flavors. Once done, carefully remove the jars and place them on a clean towel to cool.

If you prefer a quicker method, skip the water bath canning. Let the jars cool at room temperature for about an hour. Once cooled, store the jars in the refrigerator instead. This way, your pickled jalapenos will be ready to enjoy in about a week.