Step 8: Chilling the Wort
This is the point at which a wort chiller would be useful.
Without one, simply plug one side of your sink, put the pot inside, and fill it up with cold water and ice.
Stir the wort and constantly monitor the temperature. Depending on the yeast and type of beer you are aiming for a pretty specific temperature. The yeast we used is a special British ale yeast used by the Steelhead Brewery here in Eugene, and we needed the wort at 70F (about 20C) for optimum fermentation. At too low of a temperature yeast are inactive, and at too high of a temperature they die.
To further speed the cooling of the wort, you can sparge the hops with cool water--my brewing pot conveniently has markings on the inside for capacity, so we were also able to add enough water at this time to bring it up to about 4 1/2 gallons.