My guess is its dehydrated but otherwise I would think it's essentially the same as when you left it. I'd just add water and use... picking right back up where you left off.... however it may take a couple weeks to get the microbiology up to speed, so throwing some "fresh" organics on top of the bedding or mixed in would help in this regard. Of course you will likely have to add worms if you intend to get back into worm farming as I doubt the cocoons will have survived 3 years without moisture.

Yes, I do agree with you on adding moisture back into it and than in a month add worms back into it.

I really would like to know how you can tell worm castings from the bedding?

Also how do you make worm tea?

What I did 3 years ago was I would wet the beds and anything that came off at the bottom and into a bucket I use it as worm tea.

There's no real advantage to worm tea, and if you just use run-off from a bin, the liquid you're getting isn't all from fully processed worm castings. In the few places where I need to use a liquid fertilizer (for instance, for my houseplants and orchids) I put a little fully processed vermicompost into some water, mix it up and use it right away. Otherwise, just adding vermicompost to the surface of the soil on an ongoing basis is all you need to do to feed outdoor plants.