A kettle, sometimes called a tea kettle or teakettle, is a device specialized for boiling water, commonly with a lid, spout, and handle. There are two main types: the stovetop kettle, which uses heat from a hob, and the electric kettle, which is a small kitchen appliance with an internal heating element.
The word kettle originates from Old Norse ketill, "cauldron". The Old English spelling was cetel with initial che- [tʃ] like 'cherry', Middle English (and dialectal) was chetel, both come (together with German Kessel "cauldron") ultimately from Germanic *katilaz, that was borrowed from Latin catillus, diminutive form of catinus "deep vessel for serving or cooking food",[1] which in various contexts is translated as "bowl", "deep dish", or "funnel".
A modern stovetop kettle is a metal vessel with a flat bottom used to heat water on a stovetop or hob. They usually have a handle on top, a spout, and a lid. Some also have a steam whistle that indicates when the water has reached its boiling point.
Kettles are typically made with stainless steel but can also be made from copper or other metals.
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See also: Electric water boiler and Instant hot water dispenser |
In countries with 200–240 V mains electricity, electric kettles are commonly used to boil water without the necessity of a stove top. The heating element is typically fully enclosed, with a power rating of 2–3 kW. This means that the current draw for an electric kettle is up to 13 A, which is a sizeable proportion of the current available for many homes: the main fuse of most homes varies between 20 and 100 amps. In countries with 120 V mains electricity, twice as much current is drawn for the same power.
In modern designs, once the water has reached boiling point, the kettle automatically deactivates, preventing the water from boiling away and damaging the heating element.[2][3][4]
Electric kettles were introduced as an alternative to stovetop kettles in the latter part of the 19th century. In 1893 the Crompton and Co. firm in the United Kingdom started featuring electric kettles in their catalogue. However, these first electric kettles were quite primitive as the heating element couldn't be immersed in the water. Instead, a separate compartment underneath the water storage area in the kettle was used to house the electric heating element. The design was inefficient even relative to the conventional stove-top kettles of the time.
In 1902, the 'Archer' electric kettle made by Premier Electric Heaters in Birmingham, England, was marketed as a luxury item. It had an element sealed in the base of the kettle (not exposed to water), and was one of the first kettles with a boil-safe device.[5]
In 1922, Leslie Large, an engineer working at Bulpitt & Sons of Birmingham, designed an element of wire wound around a core and sheathed in a metal tube. The element could be immersed directly into water which made the kettle much more efficient than stovetop kettles.[6][7]
In 1955, the newly founded British company Russell Hobbs brought out its stainless steel K1 model as the first fully automatic kettle.[8] A bimetallic strip, heated through a pipe by the steam produced as the water comes to the boil, flexes, and cuts off the current. As little steam is produced before boiling occurs, the bimetallic thermostat is set to activate well below 100 °C (212 °F; 373 K), thus this design works even at higher altitudes where the boiling point is significantly lower. The design has since been widely adopted by other manufacturers.[4][3][9][10]
A whistling kettle is a kettle fitted with a device that emits an audible whistle when the water in the kettle starts to boil. The action of steam passing through the device causes vibration, in turn creating the sound, known in physics as a tone hole.[11]
The exact mechanism by which this occurs was not fully understood until a paper, The Aeroacoustics of a Steam Kettle, was published by R. H. Henrywood, a fourth-year engineering undergraduate at the University of Cambridge, and A. Agarwal, his supervisor, in the journal Physics of Fluids in 2013.[11][12]
Harry Bramson is the inventor of the whistling tea kettle.[13]
Automatic tea kettles are meant to make tea brewing easier, built with the capability to make different kinds of tea without much input from the user.[14] Once set, the automatic tea kettle brings the water to the specific temperature for preparing a given kind of tea, adds the tea to the water, and steeps the tea for the appropriate amount of time. This is because different types of teas must be brewed at different temperatures in order to create a full, balanced flavor.[15] Often they will make a beeping sound to alert the user when the tea is ready, and maintain the temperature of the beverage after preparation.
