"wort should be cool before you pour it into the fermenter. If it is not, refer to Chapter 7 - Boiling and Cooling, for suggested cooling methods. But before you transfer the wort to the fermenter, you may have been wondering what to do about all the hops and gunk in the bottom of the pot.
There will be a considerable amount of hot break, cold break and hops in the bottom of the boiling pot after cooling. It is a good idea to remove the hot break (or the break in general) from the wort before fermenting. The hot break consists of various proteins and fatty acids which can cause off-flavors, although a moderate amount of hot break can go unnoticed in most beers. The cold break is not considered to be much of a problem, in fact a small amount of cold break in the fermenter is good because it can provide the yeast with needed nutrients. The hops do not matter at all except that they take up room.
In general however, removal of most of the break, either by careful pouring from the pot or by racking to another fermenter, is necessary to achieve the cleanest tasting beer. If you are trying to make a very pale beer such as Pilsener style lager, the removal of most of the hot and cold break can make a significant difference."