The story of Primitivo and Zinfandel probably starts ages ago on what is now the Dalmatian coast of Croatia on the Adriatic Sea with a native vine we now call Crljenak Kastelanski. At some point in the dark past, Crljenak cross-pollinated with another Croatian variety called Dobricic giving birth to Zinfandel.

In 1967, UC Davis plant pathologist Austin Goheen was visiting a colleague in Bari, Italy and noticed that the wine he was drinking tasted like Zinfandel. This wine was made from the Primitivo Gioia variety grown on vines that look just like Zinfandel vines.

Cuttings from these Primitivo vines were brought to UC Davis and planted next to Zinfandel and tests available at that time indicated that the two were probably the same variety. In 1990 DNA testing by Professor Carole Meredith showed that they were indeed the same grape variety.

Historical records indicate that Zinfandel was planted in the United States prior to the first documented planting of Primitivo in Italy. It is theorized that Zinfandel was imported from the imperial nursery in Vienna, Austria in 1829 then re-exported to the Apulia region of southeastern Italy.

Mystery solved, right? Not so fast. Italians claim that what is now called Primativo was grown in southern Italy during the classic Greek period – 3,000 years ago.

To complicate matters even further, Professor Meredith reported in 2003 that Primativo is not Zinfandel. While the two grapes are genetically identical, they are not the same. The word primitivo literally means “first grape” marking one of the striking differences between Primitivo and Zinfandel. Primitivo will ripen about 10 days before Zinfandel in any give locality if grown side by side.

Leon Sobon is a veteran Zinfandel grower in Amador County’s Shenandoah Valley. He also grows Primitivo. “We grow Primitivo side by side with the Zinfandel on trellis,” Sobon relates. “Primitivo is genetically identical to Zinfandel and the vines look alike if you look at the shape of the leaves. But they are morphologically different. When you turn a Primitivo leaf over, it is almost slick underneath as compare with Zinfandel leaves that are fuzzy.

“Zinfandel is in one great big tight bunch with a sort of shoulder bunch on the side. Primitivo is a much looser bunch with smaller berries, almost like Syrah. All the berries in Primitivo ripen at the same time,” Sobon continues. “Primitivo ripens evenly and a week or two earlier than Zinfandel.”

Many who taste the wines side by side agree with Sobon’s assessment that Primitivo has completely different flavors than Zinfandel. According to Sobon, “Primitivo reminds you of Zinfandel but with more of a blackberry rather than blackberry/raspberry combination of Zinfandel. Primitivo is almost monochromatic in flavors. More like a claret or cabernet.”

Does it really matter whether it is Primitivo or Zinfandel? There is enough genetic and sensory tasting evidence to suggest that the two grapes produce distinctively different wines. This is a great situation for wine consumers because it will be up to them to make the ultimate determination; by the glass.