Once your foods are selected and the jars pass inspection, fill each jar and use a cloth to wipe the jar mouth to remove any dust or food particles. Leave about an inch of space in the jars for your absorbers. Add an O2 absorber (or several to match the volume of the jar—see below), place the lid on top, and screw the ring on tightly. As the oxygen absorber does its work, the jar lid should draw down from the vacuum inside. The atmosphere contains about 21% oxygen, 78% nitrogen, and 1% other gases. If the O2 absorber is sized right for the container, it should remove 99% of the oxygen and leave behind nitrogen and a slight vacuum—the perfect condition for food storage. It’s not unusual for foods to last two decades or more with this technique.