When is a Zin not a Zin? It's complicated

Zinfandel is often called California's indigenous wine, but its story is not that simple. Some of the best Zinfandel-based wines from the state's best and most historic vineyards can't use the grape name on their labels.

In these bottles, Zinfandel leads a supporting cast of grapes in a traditional blend that is now outright discouraged -- both by federal law and a skeptical market.

Those who love these wines say that while Zinfandel may be the star of these vineyards, it's even better with a supporting cast. "Zinfandel's like Beyoncé: She's beautiful, she's talented, but the women dancing behind her, they're not bad either," says JC Cellars winemaker Jeff Cohn.

The story goes back before Prohibition, but is causing controversy today. According to federal law, for a wine to be called Zinfandel or any other varietal name, it must contain at least 75% wine from that grape. The law is designed to protect consumers, but one consequence is that it has created several generations of American wine drinkers who believe a varietal wine is always better than a blend. Read more here.

Photo: Morgan Twain-Peterson, left, makes a Bedrock Heirloom Wine that's half Zin. His dad, Joel Peterson, makes a Ravenswood wine labeled Zinfandel. Credit: Robert Durell / For The Times