Yeast and Ferments

Mix some flour into a dough and bake it. The result will be a coarse, tough, indigestible cracker.

The flour and water product possesses keeping qualities, but can only be used as a food when soaked in a fluid.

A baked product if used as a nutriment must possess lightness and porosity and be so constituted that it can be easily digested.

For this reason yeast is required in bread making.