No Need for Kneed or Bread Baking for Cretins

It's essential to have steam during the beginning of baking a loaf of bread. Yeast activity accelerates as soon as the bread enters the hot oven. If you put the dough in a dry oven, the crust sets immediately, preventing the yeast from expanding the bread. By using a covered Dutch oven with this wet dough, the all-important steam is trapped inside, surrounding the loaf. This keeps the crust soft and cool longer, allowing the yeast to go to work and the loaf to grow. Enzymes in the dough are also active at this time, particularly on the warmer surface, busily working to convert starches into dextrins and other simple sugars. These compounds contribute to crust coloration and flavor. Eventually (at about 140 degrees), the yeast die off. Then the starch granules absorb water, becoming swollen and glossy. This process is known as gelatinization, and lasts until the temperature is about 158 degrees.
By preheating the heavy Dutch oven before putting the loaf in, you replicate the direct heat of professional stone hearth ovens. The heat of a Dutch oven remains much more constant than the heat in a conventional oven. It also traps much more steam inside than can be achieved by putting a pan of water into a regular oven. Regular ovens vent, so it’s difficult to keep enough steam inside. Combined with a wet dough, the superhot pan traps plenty of humidity inside. Plus, the higher the internal temperature of the loaf, the more webbing and sheen will be created in the crumb.(more from here)