These bowls, about 4L in capacity, would have a number of small nail holes in the bottom & sides to give gas exchange, as would the lid. The lid would stay on until the growing pins needed space, then I'd switch for saran-wrap or something that could stretch vertically a good 4".
I know the lack of ventilation encourages contams. The casing layer may be just enough to cover the popcorn. As it would contain little moisture, I'd consider putting together the popcorn alone in the bowl one day, letting it stitch together for 24-48hrs, dunk the mass overnight, then let drain a little, THEN case. Some of the popcorn may be used after a pre-birth flush.
I've got a stupid amount of colonized popcorn coming up, and a mad scientist itch!

(Message edited by morthos on February 02, 2005)