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.)