Zinfandel, known as Primitivo in Italy and Crljenak Kaštelanski or Tribidrag in Croatia, is a variety of black-skinned wine grape. The variety is grown in over 10 percent of California vineyards.

The grape originated in Croatia, spread to Italy in the 18th century and to the United States in the mid-19th century. This spread brought with it a variety of regional names for the same grape, obscuring its origin. In the 1990s, after a three decade search, DNA analysis revealed an identical genetic identity for these various regional names.

The grapes typically produce a robust red wine, although in the United States, a semi-sweet rosé (blush-style) wine called White Zinfandel has six times the sales of the red wine. The grape's high sugar content can be fermented into levels of alcohol exceeding 15 percent.

The taste of the red wine depends on the ripeness of the grapes from which it is made. Red berry fruit flavors like raspberry predominate in wines from cooler areas, whereas blackberry, anise and pepper notes are more common in wines made in warmer areas and in wines made from the earlier-ripening Primitivo clone.

Archaeological evidence indicates that domestication of Vitis vinifera occurred in the Caucasus region around 6000 BC, and winemaking was discovered shortly after that. Cultivation of the vine subsequently spread to the Mediterranean and surrounding regions.

The earliest known mention of this grape dates to 1444 under the name Tribidrag, as attested by don Juraj Radičević, priest of the church of Holy Cross in Vodice, in Dalmatia region of Croatia, then part of Venetian Republic. Croatia once had several indigenous varieties related to Zinfandel, which formed the basis of its wine industry in the 19th century. This diversity suggests that the grapes have been grown in Croatia longer than anywhere else. These varieties were almost entirely wiped out, however, by the phylloxera epidemic of the late 19th century. Eventually, when Zinfandel’s DNA match with Crljenak Kaštelanski was discovered in 2001 in Kaštela, it’s cultivation experienced rebirth.

The first documented use of the term Primitivo appears in Italian governmental publications of the 1870s. The name derives from the terms primativus or primaticcio, which refer to the grape's tendency to ripen earlier than other varieties. This name's appearance, 40 years after the first documented use of the term Zinfandel, was previously thought to suggest that Primitivo was introduced to Italy from across the Atlantic; however, this hypothesis has become unlikely since the discovery of the vine's Croatian origin.

Primitivo is now thought to have been introduced as a distinct clone into Italy's Apulia region in the 18th century. Don Francesco Filippo Indellicati, the priest of the church at Gioia del Colle near Bari, selected an early ("primo") ripening plant of the Zagarese variety and planted it in Liponti. This clone ripened at the end of August and became widespread throughout northern Apulia. Cuttings came to the other great Primitivo DOC (denominazione di origine controllata or "denomination of controlled origin") as part of the dowry of the Countess Sabini of Altamura when she married Don Tommaso Schiavoni-Tafuri of Manduria in the late 19th century.