Although iced coffee and cold brewed coffee both start out as water and coffee grounds, the end results are quite different from one another. The distinctions come mostly from the time and temperature at which the coffee grounds are brewed. Both methods extract the luscious flavor profiles of the coffee beans; it is simply done in different ways.
Brew Methods
In the most basic terms, iced coffee is simply hot brewed coffee that has been cooled down and poured over ice cubes. Quite the opposite, cold brew coffee is never exposed to high temperatures and instead uses time to slowly brew a coffee concentrate. Medium or coarsely ground coffee is steeped for over 12 hours in room temperature water and is then strained for a clean cup of joe. Both styles of coffee can be made at home. For iced coffee, use your percolator or coffee pot to brew hot coffee as you normally do. Once brewed, allow to cool slightly and pour slowly over ice cubes.
Cold brewed coffee is more time consuming and can take hours and even days to produce the perfect concentrate. Using a French press, place your ground coffee on the bottom, add room temperature bottled water and allow the plunger lid to gently drop on top of the grounds. With a four part water to one part coffee ratio, you end up with a rich coffee concentrate that can be diluted with milk, water or liquor and served over ice.
Flavor
The flavor of your coffee is determined by more than just the type of coffee beans. When ground coffee beans are mixed with water, the coffee’s solubles are extracted and a chemical reaction occurs. In boiling hot water (how iced coffee is brewed), coffee solubles are pulled out quickly creating a flavorful, full-bodied taste and undeniable coffee aroma. However, extremely hot water causes the chemical compounds to oxidize and degrade which is why hot coffee has a more bitter and acidic taste.
Cold brewed coffee grounds brew longer and at lower temperatures; therefore less acid is released, but so is less flavor. The resulting taste is more muted than regular coffee. It is smoother, more mild and does not have the fragrant aroma. If you are accustomed to the the more traditional coffee flavor, the sweetness and lightness of the taste may surprise you.
Caffeine Content
Although the exact caffeine content in coffee varies greatly from different types of beans, brew times, how coarse the grind is and other variables, there are a few facts that you can generally count on. The solubility of caffeine is primarily determined by temperature. In higher temperatures, significantly more caffeine is dissolved than at cooler temperatures. That means if you are using the same brew-to-water ratio, hot coffee contains more caffeine than cold brewed coffee. Even if your cold brew coffee drink has a higher ratio of coffee to water, it will usually still have less caffeine than hot brewed coffee.
Keep in mind that personal taste is subjective; there are many people who prefer cold brew over iced coffee and vice versa. The bottom line is that cold brewed coffee is smooth and sweet while iced coffee retains the quintessential coffee flavor with complexity, bitterness and acidity. As to which style of coffee is best? Give them both a try and let your taste buds make the decision.