Tea is one of the great British institutions, ranking right up alongside the NHS, the BBC and even the pub*. Although its impact on the national psyche may not quite match that made on the Japanese, who have famously based an entire way of being (chado) around the appreciation of tea, the nation’s reputation for gentility and quiet resolve is surely wrapped up in its ongoing love affair with the noble cup.

Tea was first introduced to the country in 1657, and advertised as a panacea for a preposterously wide range of conditions. It was first sold in coffee houses, which were all the rage at that time, and its popularity didn’t match that of coffee until 1850. The tradition of afternoon tea – taken with cakes and sweets at around 4 o’clock – was started by the Duchess of Bedford in 1840 and has persisted ever since, although it is neither as ubiquitous nor as rigidly defined as many foreigners seem to believe.

The drink known as English tea really has its origins in India, as does the much of the tea it is made from. Indeed, most of the tea in India is consumed in the 'English' style, despite the more obvious association with masala chai - spiced tea which is usually known simply as chai in English. Although I am going with the convention of calling this English tea, this is far from exclusively an English tradition - although for some reason tea has never been the hot drink of choice for most Scots. Throughout Britain and Ireland, as well as much of the rest of Europe, most of North America and elsewhere, if someone offers you a cup of tea it is usually safe to assume they mean milky black tea with optional sugar.

Debates on how to make the perfect cup of English tea are never-ending, despite the input of various scientific experts, the International Standards Organisation, and such luminaries as George Orwell and Douglas Adams. However, all serious tea-drinkers are agreed on one issue: The water used must be boiling when it is added to the tea-leaves. This means pouring it straight from the kettle when it has just boiled, and not adding milk alongside a tea-bag in the cup. If you belong to the school of thought which holds that milk should be added to the cup before tea, please – for the love of good tea – only apply this philosophy when brewing in a pot.

Most English tea is made using tea bags full of blended tea - and although both bags and blends may be frowned upon by the snobbier of tea connoisseurs, the truth is that the combination makes for a perfectly good cup of English tea. The blends involved in popular brands such as PG Tips, Tetley and – in Ireland and among its ex-patriate communities – Barry’s Tea tend to consist of one or more Sub-Continental tea, such as Assam or Ceylon, mixed with strong black teas from African countries, most notably Kenya. Traditional English Breakfast tea may be well-known, but it is ill-defined, and may consist of any or all of Assam, Ceylon, Keemun (a black Chinese tea) and sometimes also African tea. Earl Grey is another popular candidate for English tea-making.

English tea is usually made with cow's milk; besides adding a certain amount of milky flavour, the main effect of this is to remove most of the astringency and bitterness of the tea. This works because the proteins in the milk bind with the tannins (polyphenols) responsible for these flavours, allowing tea to be made much stronger than it otherwise can be while remaining drinkable. Studies suggest that this has the unfortunate side-effect of reducing its antioxidant power, alas. The most popular alternative to cow's milk is soy milk - which is okay, but liable to curdle a little unless you wait for the tea to cool down before adding it, and ideally add it to the cup before pouring the tea from a pot. Oat milk is better, but harder to find, as is soya cream; rice milk just about does the job, but is usually much lower in protein and hence astringency-removing power.

As I have said, it is possible to make a perfectly good cup of English tea from bags; but loose leaves brewed in a teapot will make even better tea, with a fuller flavour. Blended teas are again fine for this, but you may find that a strong brew of Assam, Ceylon or Kenyan tea is tastier still.

Recent years have seen a fall in the popularity of English tea, hit both by the resurgence of coffee houses (now overwhelmingly branded and sterile affairs, a far cry from the creative, debative hothouses of yesteryear) and by the rising popularity of other kinds of tea – green tea, oolong tea, spiced chai and herbal infusions. However – like the decline of rock and roll in 1990s America – this is a cultural phenomenon of such profundity and endurance that even at its lowest point it is seen everywhere, and it is hard to see this dip as anything but a glitch in the grand scheme of things.

*Why do all these Great British Institutions have three letters, I wonder? Also, I should mention that for some reason tea has never been the hot drink of choice for most Scots.