The tea bag is rooted in the belief that the leaves ought to removed from the hot water at the end of a specific brewing period.
At first, there were infusers — perforated metal containers which were filled with loose leaves and immersed in boiling water, and then removed using an attached chain.
They are still around, though not nearly as popular as tea bags, that are an American invention. Though not an intentional one.
A New York tea merchant, sent samples of tea to his customers in small silken bags and some of them assumed they were to be used in the same way as the metal infusers. So they dunked the entire bag into the teacup and – presto – the tea bag was born.
Of course, it was refined until it became the tea bag of today, complete with gauze-like material, a string to hang over the side of the cup, and a tag on the end with a logo on it.