On Food and Cooking

produce more noticeable quantities of sour
and unpleasant-smelling by-products. A
fermentation temperature of 80ºF/27ºC is
often suggested for a relatively quick rising
time of a couple of hours. Lower temperatures
may extend fermentation times by an hour or
more, and with them the generation of
desirable yeast flavors.
The end of the fermentation period is
signaled by the dough’s volume — it
approximately doubles — and by the
condition of the gluten matrix. When poked
with the finger, fully fermented dough will
retain the impression and won’t spring back:
the gluten has been stretched to the limit of its
elasticity. The dough is now gently handled to
reconsolidate the gluten, divide the gas
pockets, redistribute the yeast cells and their
food supply, and even out the temperature and
moisture (fermentation generates heat, water,
and alcohol). Thanks to the added moisture
and to the gluten-interrupting bubbles,