An insulating jug serves to suppress the heat exchange between content and environment. It is used to keep liquids such as tea or coffee warm. For this purpose, it must exclude all means of heat transfer as far as possible: convection, heat conduction and heat radiation. Convection is the transfer of heat energy in gases or liquids by movement. Heat conduction is the process by which heat is transferred from one substance to another. Heat radiation is the radiating of heat by electromagnetic waves in the infrared range.

Operation of the jug

The housing of a jug is usually made of metal or plastic. Underneath is a double-walled glass bulb. The glass bulb is mirrored inside. In addition, there is a vacuum in the space between its walls, which minimizes heat exchange with the environment through convection. Glass is a bad conductor of heat; it suppresses the heat exchange through heat conduction. By mirroring a jug, the heat radiation gets back into the liquid. For best insulation properties!

History of the vacuum jug

The principle of the jug is from the English chemist James Dewar. In 1874 he used vacuum vessels for his experiments. Regardless of Dewar also discovered the Chemnitz Professor Adolf Ferdinand Weinhold the principle. In 1881 he used it to mercury hardening. In 1920, the company Charlottenburger Thermos AG started series production of thermos flasks and thermoses.

Stable and durable

Vacuum jugs, which goes without saying, should keep drinks and liquids warm (or cold) for as long as possible. Usually they are equipped to hold heat for at least 12 hours. When selecting and buying it is important to pay attention to the indication of this value. Should be avoided by vacuum jugs with lower values. Thermos flasks or vacuum jugs that have a glass bulb inside are preferred – such as the Alfi vacuum jugs. They fulfill all mentioned insulating properties. Housing and interior of Alfi vacuum jugs are stable and durable. Your stainless steel case is noble to look at. Some Alfi vacuum jugs, such as the Alfi Gusto vacuum jug, impress with their insensitive, high-quality multi-layer baking finish. They are available in many different colors such as red, purple, mango or aquamarine.

Quality and design in the foreground

No matter whether hot or cold drinks – with Alfi vacuum jugs the desired temperature of liquids is maintained for hours. Since 1914, the brand Alfi stands for best quality in the field of insulated containers. Founded as „Aluminumwarenfabrik Fischbach“, the name of the short form of today’s brand name has developed. At Alfi quality and design are in the foreground. That makes the jugs and bottles to robust and reliable companions in everyday life. Whether at home or on the go – the Alfi vacuum jugs and vacuum flasks are ideal for holding hot or cold drinks. In addition to the quality of the jugs, their design also plays a role that should not be underestimated. Renowned, renowned designers from all over the world design stylish, aesthetically appealing creations for the traditional company. For example, the ball can from Ole Palsby: It has been considered an absolute bestseller for decades.

Robust and reliable companion in everyday life

Thermos flasks or vacuum jugs from Alfi work with a vacuum. Between the outer shell and the inner bottle made of high-quality, coated glass, there is a vacuum that can not conduct heat or cold to the outside. The lid of the jug is also well insulated. In general, all hot and cold drinks can be stored in Alfi vacuum jugs. One of Alfi’s bestsellers is the Helena vacuum jug. It is made of high-gloss chrome-plated, high-quality brass. The vacuum tempered glass insert convinces with the best insulation performance. Thanks to the hinged lid system, the jug can be easily operated with one hand. Basically, the „sorted“ use of Isolierkannen is important. This means that an insulated jug should be used either exclusively for tea or coffee. Especially coffee quickly releases its aroma to the insulated container. If you put tea into the vacuum jug, the last traces of the coffee will spoil the taste. It is always important to pay attention to this.