On Food and Cooking

but this results in a different kind of
fermentation. Nutrients for the microbes in
the brine diffuse very slowly from the flesh
through the waxy cuticle, and the intact
phenolic materials inhibit microbial growth.
So the temperature is kept low (55–64ºF/13–
18ºC), and yeasts rather than lactic acid
bacteria dominate in a slow alcoholic
fermentation that takes as long as a year. This
method is usually applied to black ripe olives
(Greek, Italian Gaeta, French Niçoise). They
turn out more bitter and less tart than the
pretreated kinds (an acidity of 0.3–0.5%
rather than 1%), and have a distinctively
winey, fruity aroma.
Unfermented “ripe black olives” are an
invention of the California canning industry.
They’re made from unripe green olives, which
may undergo an incidental and partial
fermentation while being stored in brine
before processing. But their unique character
is determined by repeated brief lye treatments