Would you guys recommend against sealing it, if it hasn't been sterilized?
I'd say make sure you aerate the wort everyday until you can boil it. Most dangerous stuff (botulism) is anaerobic, and might not get killed by boiling afterward.
But that's really a worst-case scenario.
In the meantime, yes, it might become a fun playground for wild yeasties, but their fun is gonna short, when you boil their a$# up.