We tend to store tea in cool, dark places - in other words, places where we're likely to completely forget about it until it's gone stale.

If you've ever come across some years-old tea in your kitchen, you've probably just binned it. "But if it is green tea, you can give it a second life," says Erik Spickschen, tea specialist and co-founder of vegan fine dining restaurant Oukan in Berlin.

"You roast the loose leaves and stems in a clean, non-stick pan over medium heat until they start to turn slightly brown," Spickschen says. This revives the inner flavour components, he says.

"The green tea will taste different than it did originally - nutty, chocolaty, with roasted notes - but it will once again be a real treat," Spickschen says.

If you enjoy green tea, you don't necessarily need to buy the most expensive kind. Kukicha, a Japanese green tea with a lower proportion of leaves, is significantly cheaper but still tastes excellent, says Spickschen.

This Japanese green tea, primarily made from the stems and twigs of the tea plant, is known for its mild, slightly nutty flavour with a hint of hay. An added benefit is that the lower leaf content compared to other green tea varieties, such as Sencha or Gyokuro, results in a lower caffeine content. – dpa