Olive oil producer Arden Kremer of Sonoma warms a small blue cup of olive oil in her hand, then sips it, coating her tastebuds with one quick, noisy slurp.
"This one is bitter and buttery, with a hint of stone fruit," she said. "It's mild, but a lot of consumers don't like things that are too strong."
She cleanses her palate with a slice of green apple and warms another cup in her hands.
"This one is much more bitter," she said. "It's peppery and grassy, with a hint of cinnamon."
Kremer's impromptu olive-oil tasting illustrated an important point: Not all olive oils are created equal.
"People don't realize that, like wine, oils will have different flavors from the different olives," she said. "And that's part of the education process."
Every year, the North Bay olive season starts in mid-November and runs through December. For more than a decade, Kremer has been educating her own palate to detect the flavors of olive oil and the tiny defects that would prevent it from becoming certified as extra-virgin in California.
The 57-year-old has served as a member of the California Olive Oil Council's Tasting Panel since its inception in 1998. The COOC panel's certification program helps consumers identify olive oils that are guaranteed to be extra virgin.
"All of the tastings are blind, to protect the consumer and producer," Kremer said. "We taste in blue glasses so you can't see the color of the oil. ... We use a scoring sheet for negative attributes and positive attributes."
Some negative attributes may include rancid (tastes like old nuts), fusty (barnyard), musty (mildew) or wine-y (vinegary.)
"We're trained to find those in small, minute amounts," Kremer said. "You really develop a palate memory."
In 2005, Olive Oil Council sent Kremer to Italy to train as an olive-oil taste panel leader. She also serves on the tasting panel for the UC Davis Olive Center and a research panel run by farm consultant and olive expert Paul Vossen in Santa Rosa.
Her love affair with olives started back in the early 1990s after she and her husband, Phil Coturri, built a home in the hills overlooking the Sonoma Valley. Kremer and Coturri — a long-time, organic grape grower in the Sonoma Valley — planted an olive grove at their home with trees imported from Italy.
Along with pioneers such as Nan McEvoy of McEvoy Ranch in Petaluma, Ridgely Evers of DaVero in Healdsburg and Lila Jaeger of Jaeger Family Estate in Napa Valley, Coturri was among the first in California to bring in trees from Italy, including such varietals as Pendolino, Leccino, Frantoio and Coratina.
The idea originated in 1991 with Lorenzo Petroni, a San Francisco restaurateur (founder of North Beach Restaurant) who owned a Sonoma vineyard managed by Coturri. Together with organic farmer Robert Cannard, Coturri and Petroni imported thousands of tiny Italian olive trees, then propagated them.
"They brought in trees twice, in large quantities," Kremer said. "Now everybody has trees."
In 1997, Kremer took a course in the sensory evaluation of olive oil through the UC Davis Cooperative Extension in Santa Rosa.
"My kids were grown, and it was harvest, so they sent me," she said. "I learned all about flavor profiles and what's needed to make good and bad olive oil."