Milk in first or last? Does your mug matter? And just why is tea brown?

These crucial questions and more were answered in The Science of Tea, a presentation given by a group of brew-loving scientists at the Cheltenham Science Festival, with the expert help of our tea buyer Simon Hill (that's him second-from-right in the picture above).

For an hour and a half, 250 people slurped and sipped their way through various types of tea while the big issues of tea drinking were explored with scientific rigour.

Simon said: “They did a blind taste test with one audience member – she tried one cup with the milk added first and one with the milk added after.

“She preferred the one with the milk in first... but she normally adds it after. And I think the conclusion is that, when pushed, people can’t really tell either way.”

As for mugs, it turns out they do make a difference.

“There was a bit about why tea can stain your mugs,” said Simon.

“China (porcelain) is less porous, so it doesn’t stain so much. And as the tannins which affect the colour stay in the tea, that helps the taste too.”

Whether the average tongue can detect the difference is another question, but for safety’s sake, you might want to pick up one of our lovely Yorkshire Tea mugs – made, naturally, from top quality porcelain.

All told, it was a fascinating glimpse into the inner mysteries of tea.

“It was really good,” said Simon. “I think the audience enjoyed the tastings and they enjoyed the slurping.

“And because we were doing the tastings, the logistics of handing out 250 cups of tea meant the audience could ask plenty of questions.”

One of which was: can you drink tea that’s been in the cupboard for five years?

No. Well, technically yes... but for the love of a good brew, please don’t.