Zinfandel fanatics are expected to come in droves — their yearly pilgrimage — to the ZAP (Zinfandel Advocates & Producers) Tasting Jan. 19 in San Francisco.

Zinfandel fans from California and beyond are on a mission to taste the spring releases before they come on the market. While ZAP is not exactly the equivalent of Paris Fashion Week, zin zealots want to check out what’s in vogue. They want to know which way the pendulum is swinging, from food friendly zins to the high alcohol blockbusters.

There will be hundreds of pours of zinfandel, offering every incarnation imaginable, from lean to full throttle. The Grand Tasting, from 11 a.m. to 5 p.m., is the biggest draw. For tickets, directions and details about the entire rollout of events, visit zinfandel.org.

The fascination with zinfandel isn’t surprising because it was California’s mystery grape after it found its way to the United States in the late 1800s. But DNA fingerprinting in the 1990s revealed this renegade grape was genetically identical to Italy’s primitivo and the Croatian variety crljenak kastelanski.

One of the best things to come from the zinfandel enigma is the outpouring of research from the Zinfandel Heritage Project. A collaboration between ZAP and UC Davis, the project was originally established at the university’s Oakville Research Station in Napa Valley beginning in 1995. The research has been a boon for farmers, growers and vintners, with a bevy of clones and cuttings for them to explore.

Wine writer Peg Melnik can be reached at peg.melnik@pressdemocrat.com or 707-521-5310.