Overview: How a factory in France produces 336,000 croissants every day - from the 21 tonnes of butter, to the 83-year-old strain of yeast that packs a flavourful punch, to the layering of very thin slices of butter between sheets of dough to create the famously flaky texture. How croissants are best served - and eaten. How 'concentrated' butter produced in north Wales enhances the shelf life of croissants. The history of the croissant, thought to originate from 17th-century Austria, and emerging in its modern French form as late as 1906. How bread played a vital role in the French Revolution.