I am 7 days into my cream stout, its resting quietly at 67 degrees, no visible signs or sounds coming from the airlock and the beer has retreated to resemble a smooth lake with a few white lilies on top. i am going to give it another week before taking a hydrometer reading and potentially transferring to my bottling bucket....oh, my question? what s this crash cooling people talk about? do i need to do this before bottling? i have the ability through my temperature controlled freezer, but what are the advantages/disadvantages?