Man has always made use of yeast, even before he discovered how to write!  The Egyptians used it to bake their bread 5000 years ago.  However, they knew nothing about the fermentation process and as they saw it this chemical reaction was nothing short of a miracle.  Up until then, cereals, broths and pancakes had formed a major part of the daily human diet.

Bread was discovered the day man realised that fermented dough could be used to make the pancakes rise, to enhance their taste and to give them new textures.
It is said that during the first century AD, the very first Gallic and Iberian breads were produced using foam skimmed from beer, i.e. the yeast which rose to the surface of the liquid during the fermentation of the beer.  This method made it possible not only to speed up fermentation but also to improve both the taste of the bread and its raising ability.