Comparison Zelmer ZCK8011 stainless steel vs Gorenje K 17 TR 2200 W 1.7 L stainless steel

The outer covering of the heater is a significant factor in determining the characteristics of the kettle because it is in direct contact with the heated water. Therefore, the material used for this coating is an essential consideration in the kettle's properties.

— Stainless steel. "Stainless steel" is the most commonly used coating for kettles as it is affordable and provides good resistance to scale buildup. However, compared to more advanced materials, it may not offer the highest level of scale resistance.

— Aluminium. Another common material, slightly more expensive and resistant to scale than stainless steel, but in general not having significant differences.

— Ceramic. Ceramic coating is known for its exceptional resistance to both scale and corrosion. Although it cannot provide a complete guarantee against scale buildup, it does tend to form plaque at a much slower rate than on surfaces made of steel or aluminium. Additionally, many of these heaters can be cleaned with more aggressive descaling products that would not be suitable for metal coatings. However, due to their high cost, ceramic coatings are typically only used in premium kettles.

— Silver. Silver is another premium material that has good resistance to both scale and corrosion. In addition, it also possesses some antibacterial properties, making it a suitable choice for those who use the kettle to store cooled boiled water. However, the cost of silver pla...ting is quite high.

A device that allows you to set the temperature to which the water will be heated — the thermostat monitors the temperature and automatically turns off the heating when the desired value is reached. In fact, water heated in a kettle does not always need to be boiled: for example, for brewing some types of tea, the optimum temperature is about 80 °C, and for preparing baby food — 60 °C. Thermopot are most often equipped with a thermostat, but there are also classic electric kettles with such a function.

A device that displays the temperature of the water in the kettle. The presence of a thermometer is useful if the water needs to be heated to a certain temperature. However, the thermometer does not automatically turn off the kettle, unlike a thermostat — this must be done manually. Also, the thermometer allows you to assess how much the heated water has cooled over time and whether it can be used without heating again.

The general shape of the body of the electric kettle.

— Conical. The most popular option: a body is wide at the base and tapering upwards. This form contributes to stability: the centre of gravity is maximally displaced downwards. However washing such a kettle from the inside may not be very convenient due to the relatively small size of the opening in the upper part.

— Cylindrical. The cylindrical shape provides more or less the same width of the body at the base and at the top. With the same height and base diameter, such kettles hold slightly more water than conical ones; in addition, such a device is easier to clean due to the wide opening for the lid.

— Inclined. The body which is inclined forward; the width of such a body is usually more or less the same over the entire height. Such kettles have an unusual, eye-catching appearance; in addition, it is easier to pour water from them — the device must be inclined at a smaller angle than with a cylindrical and even with a conical body. However, this option does not provide fundamental advantages over the same cylindrical shape, but it is more expensive, and therefore is not common.

Decorative lighting of the body or capacity of the kettle. It has mainly aesthetic value — it improves the appearance of the device. Sometimes it can serve as a kind of indicator, for example, change the colour when water is boiling.

The main material of the kettle.

Note that this paragraph primarily considers external material; the inner coating may differ from it. As for specific options, metal (usually steel), plastic and glass products are the most popular nowadays. More rare are glass with metal and ceramics (including porcelain). Here is a more detailed description of the different materials:

— Steel. Stainless steel is a popular material for kettles due to its strength, stylish appearance, and non-corrosive properties. It is available in a wide range of price categories. However, steel's high thermal conductivity may increase energy consumption and create a risk of burns. Steel is also opaque, so transparent inserts are necessary to monitor water levels. It is not suitable for teapots as it can give an extraneous aftertaste to the drink.

— Plastic. Plastic kettles are inexpensive and can be produced in various colors and transparency. They have low thermal conductivity, which reduces the risk of burns when touched. However, plastic is prone to scratches and can fade over time. Inexpensive plastic models may emit an unpleasant smell and taste when heated, but higher-priced models may use better quality plastic or have a metal lining to prevent this issue. Some high-end plastic materials are available b...ut cost more.

— Glass. Glass kettles have a visually appealing and transparent appearance, allowing you to easily monitor the water level without any special indicators. This is especially useful for teapots, as it enables the user to monitor the colour and saturation of the tea during the brewing process. Glass containers do not affect the taste or smell of the drink, which is highly beneficial for tea drinkers. Although glass is considered fragile, it is difficult to break such a container in reality. However, one of the downsides of glass containers is that any scale or contaminants inside the container are easily visible from the outside, requiring extra care to maintain their appearance. The thermal conductivity of glass is average, making it less prone to heat transfer than steel, but more so than many types of plastic. Therefore, touching a heated glass kettle should be avoided to prevent the risk of burns.
It should be noted that glass kettles often have parts made of materials other than glass. Usually, the top and bottom, as well as the handle, are made of plastic or a combination of plastic and metal. However, if these parts are mostly made of metal, the material is referred to as "glass with metal."

— Glass with metal. There are glass kettles that have metal top and bottom parts, with only a plastic insert in the lid for convenience purposes. These teapots are considered more advanced than the regular glass models that use plastic, as metal adds a sense of solidity and enhances durability. Also, since the contents of the kettle do not come into contact with plastic, the possibility of foreign tastes and odors is almost non-existent. However, such teapots are relatively expensive, although there are also affordable options available.

— Ceramics. Ceramics have a distinct advantage in terms of aesthetics as they offer a stylish appearance, making them an ideal choice for retro-style kettles or those with a classic design. Moreover, they are usually adorned with unique patterns and designs. Apart from their appearance, ceramic kettles do not affect the taste of the contents and provide excellent heat retention due to their thick walls. However, they are heavy and vulnerable to shocks, their opaque cases make it difficult to check water levels without opening the lid, and they lack water level indicators. Therefore, if appearance is a priority, ceramics can be an attractive option despite these drawbacks.

— Porcelain. Porcelain is a type of ceramic material that is highly valued for its prestigious appearance and is considered expensive. However, it is also fragile and requires delicate handling, which is why it is not commonly used in electric kettles.