The return of the programme exploring the secrets behind mass-produced food, with Jimmy Doherty heading to Paris to find out why baguettes go stale so much faster than sliced loaves of bread. Matt Tebbutt is in Italy to investigate why buffalo mozzarella is much more expensive than that from cows and Briony May Williams discovers the surprising secret to the making of mushy peas.

Matt Tebbutt investigates an intriguing claim about tomato ketchup bottles, Kate Quilton discovers how oysters turned from a Victorian bar snack to a wallet-busting luxury, and Amanda Byram uncovers the difference between medium and large eggs.