The best reviews we found focus on electric kettles, which almost always boil water about twice as fast as stovetop kettles -- in four to five minutes as opposed to seven to 10. The best comparative tea-kettle reviews come from Cook's Illustrated magazine, the U.K.-based Which? magazine and the New Zealand-based Consumer magazine. All three publications put tea kettles to the test, focusing solely on electric models, but most of the top picks from Which? magazine and Consumer magazine aren't sold in the United States.
The testing criteria at Which? magazine goes above and beyond; the editors consider unusual factors such as "smudgeability" -- determining whether fingerprints easily show on the kettle. Which? editors also took tea kettles' mineral filters into consideration. These filters, sometimes called limescale filters, have a mesh trapping in the spout of the kettle that collects mineral deposits that otherwise could build up in the kettle over time. Limescale not only looks unsightly on kettles, but also can interfere with heat transfer and ultimately the boiling time. While the test at Which? is thorough, many of the recommended tea kettles are either exclusive to the U.K. or have been discontinued. The same can be said of Consumer magazine, whose testing of 10 kettles focused on boiling speed, ease of use, energy efficiency, features, and their most important quality, noise.
Cook's Illustrated magazine's report on tea kettles is detailed, but editors test far fewer kettles than Which? magazine (eight versus more than 150). But the report offers detailed information (such as exact boil times) and helpful narrative comments. In a separate report, Cook's Illustrated magazine tests four tea kettles made for use with loose tea. Testers use the same tea and a four-minute steeping time, and they judge each model based on the quality of the tea, containment of loose tea leaves, ease of use and cleaning. Finally, in its most recent coverage of tea kettles, Cook's Illustrated magazine editors evaluate five adjustable electric kettles for boiling time, ability to maintain water temperature and other features.
A number of people prefer stovetop kettles for their simplicity and because they are available in many more materials, colors and styles, allowing consumers to coordinate them with their kitchen decor. Sean Paajanen, former coffee/tea guide for About.com, says "You don't need a fancy electric kettle to boil water." This sentiment is echoed in user reviews on consumer websites such as Amazon.com.
To analyze durability and ease of use in real-world conditions, we turned to owner-written reviews on sites such as Overstock.com, Walmart.com and Amazon.com. These retail sites have dozens of tea kettles available, many of which have received several dozen reviews or more. We also found some useful feedback on tea kettle manufacturer sites and at the online foodie forum Chowhound.com.