Jimmy Doherty, Kate Quilton and Matt Tebbutt uncover more unusual, intriguing and surprising secrets behind the food we eat. What makes some tea more expensive than other tea? At one of Kenya's largest tea plantations, Jimmy discovers that tea comes in multiple grades and flavours, and every batch can be subtly different. So how can the big tea bag manufacturers produce a brew that tastes the same each time? To find out, Jimmy meets a man whose taste buds are insured for one million pounds, in the inner sanctum of one of the UK's largest tea producers. Kate keeps seeing rosemary listed as an unlikely ingredient in hundreds of different products, from chocolate chip cookies to ice cream, so how come none of them has a hint of rosemary flavour?