A cast iron kettle is a kitchen or camping implement used for rapidly heating and boiling water. An extremely durable alloy, cast iron can withstand extreme heats. When formed into a kettle, it is an efficient means of both heating liquids and keeping them warm.
Some of the first cast iron kettles were designed to be used over open flames. The metal is durable enough to sit either in a fire or just atop one. Before modern stoves with heat controls, a cast iron kettle was one of the most reliable ways to heat water or liquids like soups. Other metals discolor or warp in flames, which can alter the taste and quality of the contents as well as damaging the vessel.
Cast iron not only heats quickly, it also heats evenly. For this reason, the cast iron kettle remains popular today, even though it is not always needed anymore. The metal distributes warmth from the bottom up the sides and through the center. It also retains heat long after it has been removed from the fire, making it an efficient way to keep water warm.
Most of the time, a cast iron kettle’s shape is dictated by its intended use. Vessels that are designed to sit slightly above flames, on an elevated rack or atop a wood stove, for instance, are often flat bottomed. These typically resemble more modern tea kettles, often with rounded sides, a pointed spout, a handle, and a small lid.
A cast iron kettle of this variety is typically used for brewing tea. Tea purists are particularly fond of cast iron tea kettles because of the belief that tea leaves should steep for only certain periods of time in very hot water. The cast iron keeps the temperature consistently hot, which many believe leads to a more flavorful, better brew.
These kinds of kettles are also popular among wood stove owners. Wood stoves are generally very energy-efficient ways to heat homes, but they also tend to create a lot of smoke and have a tendency to produce very dry air. Stove owners counteract this dryness by boiling water, which releases moisture into the air. Boiling the water in a large-capacity cast iron kettle is a worry-free and often attractive way to regulate humidity. Cast iron humidifiers are often sold as "wood stove kettles."
A cast iron kettle that is designed to sit directly in a fire usually looks more like a cauldron than a cast iron tea kettle. Most of the time, a cast iron pot of this variety has legs built into its base. These legs are also made of cast iron, and give the pot some stability in the flames. A cast iron cauldron does not usually have a spout, which prevents embers or other debris from falling into the boiling liquid.