How to Brew Iced Coffee
You don't brew ice coffee by cooling down coffee that has been brewed normally. During the cooling process there would be excessive loss of volatiles during the cooling process, unless you can cool the brewed coffee without exposing it to any air.
To brew ice coffee properly, the coffee is brewed using half the amount of water during the brewing process. The trick is to properly control the extraction time. Remember, when you're using the drip method, you shooting for a four minute extraction time. After brewing, or during brewing with the espresso and drip methods, the hot infusion is poured or dripped directly into a cup or container containing ice (crushed is preferable). The amount if ice should be what would be needed to produce the desired drinking ratio in the final infusion. When making the ice there are two things to remember. Use the proper water, and make sure the water is frozen in measured containers so that you can determine the final drinking ratio. Again, when in doubt, always brew coffee on the strong side and then cut with water, if necessary.