The biology in worm castings need to stay hydrated, need to remain fed with some sort of organic matter (which may be present in fresh worm castings), protected from sunlight, and kept moist. If you think of microbes like people, then if you give them water, food, and protection from the elements, you should be good!


Here is a short video with some great info. Let me know if you have any questions or if I can be of further assistance. 


How to Store Worm Castings