The British claim to know a thing or two when it comes to making a good cup of tea.

The beverage is a cultural institution in the UK, where an estimated 100 million cups are drunk every day.

But now a scientist based more than 3,000 miles (5,000km) away in the US claims to have found the secret to a perfect cuppa that many Brits would initially find absolutely absurd - adding salt.

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It turns out that it is not a new idea - the ingredient is even mentioned in Eighth Century Chinese manuscripts, which Prof Francl analysed to perfect her recipe.

"What is new is our understanding of it as chemists," Prof Francl said.

She explains that salt acts as a blocker to the receptor which makes tea taste bitter, especially when it has been stewed.

By adding a pinch of table salt - an undetectable amount - you will counteract the bitterness of the drink.

"It is not like adding sugar. I think people are afraid they will be able to taste the salt."

She urges tea-loving Brits to have an open mind before prejudging her research, which she has documented in her new book Steeped: The Chemistry of Tea, published by the Royal Society of Chemistry.