I've heard of that trick with eggs, but instead of shortening, using parafin -- which won't go rancid. I would imagine beeswax would work just as well to if you already had an apiary. And then otherwise its standard pantry storage (cool, dry, dark, etc.. ) and they'll last at least a year or so. Probably also good to develop that habit of cracking them individually in a small bowl first and then adding to what you're preparing just incase you hit a bad one, so you don't ruin the whole batch.