Why was it not permitted for the priest of
Jupiter, whom they call the Flamen Dialis, to touch
either flour or yeast?1
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,2 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 putrefaction3; at any rate if it goes too
far, it completely sours and spoils the flour.
[p. 163]