I just started my first culture by using a mason jar and the lid off of a parmesan cheese container with the "pour side, shake side" type of lid. On the pour side, or big opening side I cut off the flap of plastic that seals the lid, on the shake side, I cut out the plastic pieces between the holes but left the plastic flap. Then I took some fine mesh cloth that I had and placed it over the jar and screwed the lid on over it. The last step of the process was to cut out the mesh from the shake side and close that side of the lid.

So far no escapees! I haven't had a chance to test it out and see how well it works, but the concept solid.