There are many things I look forward to when visiting the US – tacos, cherry pies, cheese on everything – but the tepid tea is not one of them. Across the Atlantic, if it’s not iced then it’s dangerous, so I confess to a little scepticism when I heard Prof Michelle Francl of Pennsylvania’s Bryn Mawr College’s claim to have cracked the secret of a perfect cuppa in her new book, Steeped: The Chemistry of Tea. And that secret involves salt. Given the lukewarm water commonly provided with teabags in the US, I’m encouraged to see that Francl places great emphasis on heat, calling for the mug (or pot) to be warmed before use – though I’m not allowed to use my favourite giant cup. A short and stout vessel will, she says, provide better insulation, and the hotter the tea is kept during the infusion process, the better the extraction of caffeine and antioxidants. I say all this as if I’m not involved, but instead of leaving my leaves to steep in peace, Francl has me energetically dunking and squeezing the teabag to speed things up and reduce the risk of any sourness. Frankly it’s a bit of a faff given I’m simultaneously also having to heat milk to reduce the risk of it curdling (has this ever actually happened to anyone?), and sprinkling in salt, which Francl claims will temper any bitterness. I can’t help agreeing with George Orwell, who said in his own 11-point guide to making the perfect cup that “tea is meant to be bitter, just as beer is meant to be bitter” – arguing that adding sugar to disguise this aspect of it was quite as ridiculous as seasoning it with pepper or salt. That said, I find I’m not averse to the savoury notes a pinch of salt brings out … but what I cannot, and will never forgive is the hot milk. Heating milk changes its flavour, and in the end this cup of tea tastes like that first brew after a holiday, when you have to break out the emergency UHT. To be honest, Orwell, Francl and I agree on many things, from taking the teapot to the kettle rather than the other way around, to avoiding the shallow cups that mean that “one’s tea is always half cold – before one has well started on it”. Orwell favoured Indian or Sri Lankan black tea: “China tea has virtues which are not to be despised nowadays – it is economical, and one can drink it without milk – but there is not much stimulation in it,” wrote Orwell. “One does not feel wiser, braver or more optimistic after drinking it. Anyone who has used that comforting phrase ‘a nice cup of tea’ invariably means Indian tea.” Francl and I like (Indian) Assam more specifically. But the great transatlantic divide remains – I’m sorry, but for me warm milk in tea goes straight into Room 101. So here’s my counterattack for a perfect British (or Irish) cuppa: Warm the pot (or mug, but you get second helpings out of a pot) by filling with hot water. Boil the kettle again. Meanwhile put a heaped teaspoon of loose leaf (I like Scottish or Irish breakfast blends for their high Assam content) or one teabag per person into the pot or mug, adding an extra spoonful of loose leaf to the pot (but no extra bag) and place this nearby. Fill with boiling water and leave to brew for four to five minutes, then remove the leaves or bag, pour if necessary. Add milk (preferably whole) to taste; I like it the colour of wet sand. Clasp cup with both hands and savour five minutes of pure comfort.