The film that forms at the edge of the cup when the tea cools and that clouds the tea is called tea cream and is caused by the formation of complex compounds of caffeine, polyphenols, proteins and calcium and magnesium salts, the minerals that make water hard. Under the influence of the oxygen in the air, larger molecular structures form that are not soluble in water, and they separate. The harder the water (in other words the more calcium and magnesium salts it contains), the more compounds are formed.

Using water filters that soften the water reduces the formation of these brown deposits.

Another way to soften very hard water is to boil it for 2–3 minutes longer. This causes the calcium carbonate in the water to become insoluble and to collect on the bottom of the pot as light-coloured limescale.

You can enquire into the hardness of the water in your area at the water works. In any case, this film does not affect the taste of the tea, and has no health effects whatsoever

When a teapot has been used for some time, a patina forms on it. The patina has no effect on the taste of the tea and does not need to be removed. All you should do is rinse the teapot with hot water before and after you use it. You should never put detergent in the teapot.

Tea should always be kept in securely closing containers, away from heat sources and in an absolutely dry place. Tea tins, containers of brown glass or porcelain containers are ideal. Plastic containers are not recommended. All containers should be used only for tea so as not to affect the fine aroma of the tea.

A British tradition that is now enjoying a comeback. High tea is afternoon tea and more – savoury sandwiches, petit fours, fruitcakes and of course tea. At high tea, you not only drink but also eat.