Zinquest and the 20 year mystery

Friday, 4. August 2017 - 11:15

Dr Carole Meredith, UC Davis

Iva Drganc, one of three enthusiasts who organised ‘I am Tribidrag’, a conference dedicated to just one grape variety, admits, “People told us we were crazy.” The 120 or so international delegates who descended on Split’s Hotel Park at the end of April, including luminaries such as Jancis Robinson MW and Dr José Vouillamoz, clearly thought otherwise.
Why did this obscure Croatian grape, known only through historical records, deserve its own two-day event?

DNA detectives
Grape genealogy frequently confounds as much as it illuminates. Tribidrag is better known as California’s Zinfandel, or Puglia’s Primitivo. In its native Dalmatia (Croatia’s southern coastal region), the cultivar also appears as Pribidrag or the tongue-twisting Crljenak Kaštelanski. Neighbouring Montenegro also cultivates it as Kratošija.

Glibly reeling off these synonyms is only possible due to 20 years of research undertaken by a transatlantic team. Zinfandel’s origins had been a mystery for a century when Croatian émigré Miljenko ‘Mike’ Grgich noted that California’s Zinfandel vines reminded him of his homeland’s Plavac Mali. He urged UC Davis’ Professor Emerita Dr Carole Meredith, one of the world’s foremost experts in grape DNA, to investigate. She embarked on Zinquest in 1997, commencing one of wine’s most compelling detective stories.

Attempts to match Plavac Mali and Zinfandel lead to a dead end. Realising she would have to travel to Croatia to make headway brought a new challenge – Meredith knew no one in the Croatian scientific community. Serendipity provided the solution, as University of Zagreb professors Edi Maletić and Ivan Pejić contacted her coincidentally in December 1997 in search of a grape DNA expert who could help with their research into native Dalmatian varieties. 

Over the following four years, this academic power trio sourced and analysed hundreds of Dalmatian vine samples, using DNA-matching tools pioneered at UC Davis. Over 40 indigenous varieties were identified, but frustratingly none were Zinfandel. However, many were clearly related. As Meredith related at the conference: “It was a jigsaw puzzle. We found all these pieces of the viticultural picture, but one big piece was missing – and that was Zinfandel. The big question: ‘Is it still here, or is it extinct?’”

A candidate for the missing link was Tribidrag, a variety mentioned in historical documents dating back to the 1500s. The challenge? It had not survived, despite appearing to be important in its day. The most recent sample was a leaf cutting from 1924, preserved in a herbarium.

In 2001, the team discovered a few old vines growing in the village of Kaštela, near Split. Locally known as Crljenak Kaštelanski, or ‘Red from Kaštela’, this near-extinct cultivar turned out to be the Holy Grail. Zinfandel had finally discovered its roots.

From this revelatory moment, it took a further six years to prove the theory that Crljenak Kaštelanski, Pribidrag, and Tribidrag were one and the same. Improved DNA-analysis tools became available in 2006, enabling analysis of the elderly Tribidrag sample. It was identical, and the team finally had closure. Nonetheless, Professor Pejić dropped a minor bombshell at the conference, warning, “We [still] do not have evidence that this variety was born in Croatia.” More research is needed to prove its exact origin, a task that may even prove impossible.

Two academics from Montenegro, where research into the variety is also ongoing, were present at the conference. Their comments implied that the Croatian team had sidelined its neighbour’s part of the story, and demonstrated the sense of competition to claim the variety once and for all. Let’s hope that Balkan tensions don’t cloud any further progress. In any case, at the time of writing, Dalmatia presents the most compelling evidence of being Tribidrag’s home.

So much for a good story. Zinfandel has been responsible for oceans of cheap, sugary plonk over the past few decades. This writer needed convincing that Tribidrag is the noble variety that history suggests. Help was on hand at the conference, and from some 30 examples tasted there were plenty of high points. Personal favourites included Ravenswood’s firm-structured Old Hill Zinfandel 2013, Mimica’s brooding Pribidrag 2009, and Morella’s elegant Primitivo ‘La Signora’ 2011.

Edi Maletić related how the variety was coaxed back into production in Dalmatia from a mere 25 surviving vines. In 2003, 2 kg of fruit harvested by the University of Zagreb’s agricultural facility produced a single bottle of wine. By 2007, there were enough vines to yield a barrel. Ten years later, some 15 Dalmatian producers are making Tribidrag commercially from just under 100 ha of vines.

This exponential growth shows the high level of interest in a variety which can be exported to the US, using a name already well known on the market. That said, not everyone is happy with the Tribidrag moniker, with some producers preferring locally dominant names like Crljenak Kaštelanski. Many include the helpful ‘Zinfandel’ translation on their labels.

This conference validated the variety’s importance on many levels, but it also documented something bigger. Zinquest cemented Croatia’s place on the world wine map, while forging many friendships and cultural exchanges between teams in the US, Croatia, and beyond. As Jancis Robinson MW concluded, “A grape played a part in diplomacy and human relationships.” ‘I am Tribidrag’ could not have hoped for a more noble justification.
Simon Woolf

This article first appeared in Issue 3, 2017 of Meininger's Wine Business International.