Jimmy Doherty, Kate Quilton and Matt Tebbutt uncover more unusual, intriguing and surprising secrets behind the food we eat. Kate visits Israel to unearth the mystery ingredient that makes icing sugar so light, fluffy and powdery. Her journey takes her via a dip in the Dead Sea to an enormous phosphate mine in the desert, where all is revealed. In Italy, Jimmy investigates the difference between risotto rice and long grain rice. An early morning trip to a bustling rice auction and a visit to a flooded rice field shed some light. Back in the UK, Jimmy challenges renowned Italian chef Gennaro Contaldo to knock up a risotto using long grain rice; can it be done? And where do pre-packed sandwiches' crusts go? Matt discovers that one sandwich maker has come up with an innovative - and surprising - way of putting the waste bread to good use.