Reply to Jo: This liquid is simply the fluid that was contained within the vegetable material that has run down and been collected. As you'll know, plant tissue is largely made up of water, and this solution will contain a mix of nutrients. The exact composition will vary depending on what you added to your worm bin.
It's useful stuff, so I'd suggest using it during the growing season. Just dilute at the rate of about 1 part to 10 parts of water to use on crops, flowers, trees, shrubs, etc.