you can pour any time you have a stable emulsion. the easiest way to recognize one is if you reach trace (thickening) but you don't REALLY need to get there. and you can pour at thin trace (just slightly thickened - like cream), or thick trace (like pudding) or anywhere in between.
the only thing you REALLY need to be sure of is that the soap mixture doesn't separate out (oils and water) before you pour.