A tea cosy (American English: tea cozy) or tea warmer is a cover for a teapot, traditionally made of cloth. It insulates a teapot, keeping the contents warm. Their use predates the invention of vacuum bottles as a means of keeping hot liquids hot. Tea cosies may have padded inserts that can be removed and washed.
Some tea cosies are hand-knitted, resembling woollen hats, some even feature a "bobble" (pom-pom) on top, which may also serve as a handle to remove or lift the tea cosy. Sometimes, if the tea is served in a restaurant or in a hotel, the teapot is covered with a tea cosy that has a metal exterior to protect the inner fabric of the cosy from wear and tear and also to further improve the insulation of the teapot. A special tea cosy is the so-called tea lugger, which enables the hot teapot to be carried around easily.
Tea cosies may sometimes be made in matching sets with items such as tablecloths, oven gloves, or aprons. Cloth tea-cosies may be embroidered, perhaps to complement a fine set of china. Some have been made with hidden pockets to be filled with fragrant herbs or flowers, similar to a potpourri.
Although the history of the tea cosy may begin when tea was introduced to Britain in the 1660s, the first documented use of a tea cosy in Britain was in 1867. It is probably the Duchess of Bedford who, by establishing the activity of afternoon tea in 1840, would have brought the popularity of the tea cosy. Afternoon tea was the time for networking and keeping up to date with aristocracy gossip and topical news. With all the chatter at teatime the teapot would get cold, which would have at times cut short some tea parties. And so, the tea cosy came about. Tea cosies then flourished during the late 19th century, where they appeared in many households across Britain, motivated by the obsession of decorating and covering objects characteristic of the Victorian era.