For the flavors to meld, age the eggnog in the refrigerator for at least 1 week. If you want to bottle the eggnog (before the whipped egg whites and cream are stirred in), follow the step-by-step guide in this story for bottling soda pop. Unlike the soda recipes, eggnog does not ferment (so there’s no danger of explosion); it just ages under refrigeration. The actual bottling process is the same, though.