Vinegar Jalapeno Peppers Sterilize pint or half pint canning jars. Into each jar, place a clove of garlic (optional), and a sprig of Mexican oregano (also optional, but highly recommended). Pack the washed peppers into the jars. For a hotter product, prick each pepper a couple of times with a fork (I don't know why, but it seems to work). Fill the jars with boiling vinegar to cover the peppers well. Cap. My grandmother never processed these, just stuck them on the shelf for a couple of months to marinate. On the rare occasions when I've made 'em, I keep the jars under refrigeration, just to be sure. Please note I am NOT a canning/preserving expert -have done VERY little of this (got my fill of it as a kid). I've only made these a couple of times as an adult, and they turned out fine, but surely there are more expert opinions out there....