That is weird. I have not had that much condensation in my UDS and temps around here have been in the 40s.
Are you sure it is water? I would think it would have evaporated when you heated the drum.
Could it be any oil that was used to season the drum? When i seasoned my drum I sprayed the interior with a healthy helping of spray cooking oil and ended up with a bunch of it on the bottom of the drum after the seasoning burn. I sopped it up with some paper towels when it cooled and haven't had any standing fluids on the bottom since.