[109] Why was it not permitted for the priest of Jupiter, whom they call the Flamen Dialis, to touch either flour or yeast?[253]
Is it because flour is an incomplete and crude food? For neither has it remained what it was, wheat, nor has it become what it must become, bread; but it has both lost the germinative power of the seed and at the same time it has not attained to the usefulness of food. Wherefore also the Poet by a metaphor applied to barley-meal the epithet mylephatosas,[254] if it were being killed or destroyed in the grinding.
Yeast is itself also the product of corruption, and produces corruption in the dough with which it is mixed: for the dough becomes flabby and inert, and altogether the process of leavening seems to be one of putrefaction[255]; at any rate if it goes too far, it completely sours and spoils the flour.