Two prehistoric discoveries laid the foundation for the transformation of grains into breads and noodles, pastries and cakes. The first was that in addition to being cooked into a porridge, pastes of crushed grain and water could also be turned into an interesting solid by cooking them on hot embers or stones: the result was flat-bread. The second was that a paste set aside for a few days would ferment and become inflated with gases: and such a paste made a softer, lighter, more flavorful bread, especially when cooked from all sides at once in an enclosed oven.