metabolism and growth. The yeasts and 400
generations of winemakers, who noticed and
cultivated those incidental pleasures, made a
tart alcoholic liquid into something much
more stimulating.
Beer
Wine and beer are made from very different
raw materials: wine from fruits, beer from
grains, usually barley. Unlike grapes, which
accumulate sugars in order to attract animals,
the grains are filled with starch to provide
energy for the growing embryo and seedling.
Yeasts can’t exploit starch directly, and this
means that before they can be fermented,
grains must be treated to break down their
starch to sugars. While it’s true that grapes
are much more easily fermented — yeasts
begin to flourish in the sweet juice as soon as
they break open — grain has several
advantages as a material for producing