Not sure where you got this info.

Mine sits in cubies for weeks before it goes into a settling barrel, where it stays for a couple of weeks _at least_. Then I filter it and it sits in the filtered oil barrel waiting to be pumped for more than a week (the filtered barrel only gets emptied once a year or so around here).

Nothing shows evidence of growing in my oil collection, ever. Having recently been heated to a zillion degrees probably leaves the food pretty sterile, and vegi oil doesn't' seem to be too friendly to bacteria (or Wesson oil would have killed us all by now). I'd be interested in some experamental data thouugh, if somebody has a culture dish, incubator and microscope ;)