What shape of tea bag should you buy for a better brew?

It was a question that might have puzzled the Sphinx, but the answer lies in a simple pyramid.

Due to a storm in a teacup, the question of whether a pyramid-shaped tea bag or a round tea bag brews the best cup of tea has finally been answered — by the British Advertising Standards Authority of all people.

The makers of Tetley tea bags are probably wishing they’d had a nice hot cuppa instead of indulging in a mug’s game over claims that a rival product tasted better than theirs.