We Brits really love our crisps, eating 17 million potatoes-worth of them a day! As the second series of the behind-the-scenes documentary continues, Gregg Wallace follows the snack’s process from farm to finished product, visiting the gigantic Walkers factory in Leicester – which produces five million packets of crisps a day – and having his mind blown by the incredible peeling, slicing, seasoning and packaging machines. Cherry Healey gets into the science of the perfect potato, while historian Ruth Goodman attempts to settle the age-old question of who invented the crisp. Was it an American chef – or did Brits get there first?