Hondarrabi Zuri = Courbu Blanc; An Investigative Report

A few weeks ago, I wrote about the Hondarrabi Zuri grape.  The way things typically work around here is that I do a few hours of research, write my post and move on.  This post was different, though.  The first source I consulted, the online version of the Oxford Companion to Wine, had as the very last sentence "DNA profiling has surprisingly shown that Hondarrabi Zuri is the same as the American hybrid Noah."  If true, this would be a shocking fact as it would represent, as far as I know, the only case in all of the EU where a hybrid grape, particularly an American hybrid grape, was not only the most widely planted grape in a given region, but was also one of the recommended grapes for cultivation there.

I set about feverishly to try to track down the source of that bit of information.  The OCW rarely directly cites sources for their entries online, but when doing research for other posts on the blog, I've been pretty successful in finding the original source material for the OCW's claims.  This case was different, though.  After hours and hours of searching, I had found nothing.  The best  I was able to do was to find a pair of papers written in 2003 (citations below) that analyzed a bunch of different Spanish grapes using DNA microsatellite analysis.  Both papers found that the sample of Hondarrabi Zuri used had a genetic profile that was wildly different from the other samples.  The paper by Martin, Borrego, Cabello & Ortiz offers the "probable hybrid origin" of Hondarrabi Zuri as explanation for this wild variation, but they give no further information.

I wrote my post with this information at hand, but ultimately wasn't satisfied with where I had ended up.  The next day I emailed Dr. Jesus Maria Ortiz, one of the authors of one of the papers I had read, in the hopes that he could help me clear the issue up.  Dr. Ortiz clarified that there was a grape variety grown in the Basque region of Spain for many years that was called Hondarrabi Zuri which was almost certainly a hybrid grape.  It had the noted "foxy" aroma and flavor that many of these grapes can have as well as having ampelographic features that were more consistent with a hybrid grape than with a v. vinifera grape.  This grape wasn't the same as the grape being used for wine production in the Basque region, though, and, in fact, according to Dr. Ortiz, this hybrid grape has virtually disappeared from the Basque region altogether.  The grape being used to make Txacoli wines was a full vinifera grape, unrelated to the hybrid grape, and he kindly provided me with the DNA microsatellite profile for the vinifera Hondarrabi Zuri which, it turns out, is completely unrelated to the Hondarrabi Beltza grape also cultivated in the region.

A brief aside: why are they both called Hondarrabi if they aren't related?  There's a town called Fuenterrabia (the Basque name for the town is Hondarribia which means "sand ford" in the Basque language) on the Bidasoa River which is very near the border between Spain and France.  Dr. Ortiz believes that several grape varieties came into Spain from France and were planted around this town (as we'll see below, nearly all of the Hondarrabi Zuri grapes are ultimately from France, though Hondarrabi Beltza's origin is unclear).  When they were planted elsewhere in the Basque country, they were given the Hondarrabi prefix to indicate where they had come from.  Zuri simply means "white" in the Basque tongue while Beltza means "black."

When most of these DNA studies are done for wine grapes, the scientists typically don't go out into the fields themselves to gather plant matter.  There are collections at various universities called "germplasm collections" which are filled with plants that were collected at some point from the field, but which are maintained by the university for the purpose of having a source of genetic material for a given plant on hand at all times.  In this case, for both of the studies cited above, the research teams used samples from the Spanish National Grape Collection at El Encin in Madrid.  For whatever reason, the vine stored at El Encin and marked as Hondarrabi Zuri was the hybrid grape and not the vinifera one.  When these vines are initially collected from the field, the researchers have to rely on ampelography and local lore to tell them what the name of the grape they are picking actually is.  Think about it: if they're collecting the vines for the purposes of genetic research, then the genetic research hasn't yet been done on the vines they're collecting.  Mistakes can be made in the field and a grape can be mislabeled in the germplasm collection, leading to trouble down the line.  In this case, here's what I think may have happened.  The germplasm collection contained a vine called Hondarrabi Zuri and one called Hondarrabi Zuria (both Zuri and Zuria mean "white").  When the research teams ran the analyses on these two samples, they turned out to be identical, which isn't all that unusual and, in fact, is one of the primary reasons scientists run these tests.  I think what may have happened was that these two grapes are different in the field, one being the vinifera grape used for Txacoli and the other being the hybrid grape, but two samples of the hybrid were taken and labeled by mistake.  This is pure speculation, but it seems plausible to me.

I asked Dr. Ortiz about the relationship between Hondarrabi Zuri and Beltza because I hadn't seen anyone specify what their relationship was, which seemed odd given how similar their names were.  The only mention I'd seen was in the Oxford Companion to Wine, which didn't have an entry for each grape, but rather had a single entry under the heading "Hondarrabi" where they indicated that it was a family of grapes (which would imply that Hondarrabi Beltza was also a hybrid, if their claim about Noah were true).  Given the information that I had obtained from Dr. Ortiz, I contacted the OCW and heard back from them a few hours later.  Julia Harding, MW, sent me a very nice email saying that they agreed with my complaint about the use of the word "family," and they have since struck it from the online entry (though there is still only a single entry for Hondarrabi).  She also told me that she and Jancis Robinson had been working with Dr. José Vouillamoz on their new book about grapes (which is due out soon and whose publication I am anxiously awaiting), and the bit about Hondarrabi Zuri being the same as the American hybrid Noah came from Dr. Vouillamoz's personal research, which had not been published.

She forwarded my query on to Dr. Vouillamoz who I then struck up a correspondence with.  Dr. Vouillamoz confirmed that the identification of Hondarrabi Zuri with Noah was done by comparing the sample of Hondarrabi Zuri available at the Spanish National Grape Collection at El Encin in Madrid (which was used by both papers cited previously) with a sample of the Noah grape in the collection of the Agroscope in Switzerland.  Based on this, he and the editors of the OCW had concluded that Hondarrabi Zuri = Noah.  I forwarded my correspondence with Dr. Ortiz to Dr. Vouillamoz to see what his take on our conversation was.  At the same time, I emailed Dr. Ortiz again to ask why the sample for Hondarrabi Zuri at the Encin was the hybrid and not the more widely planted vinifera grape.  Dr. Ortiz has responded that he does not know, but that the fact of the matter is that the sample at El Encin marked as Hondarrabi Zuri is not (or was not, I don't know if the germplasm collection has been updated recently) the same as the grape grown in the field and approved for use by the DO.

Dr. Ortiz also forwarded my question along to Dr. Felix Cabello.  In the text of his email to Dr. Cabello, Dr. Ortiz remarks that at some point after their 2003 study, the team picked up a grape referred to as Hondarrabi Zuri Zalla (so named because it was found around the Basque village of Zalla, I'm assuming), which is the grape that was approved by the DO and which is used for the production of Txacoli wines.  This Hondarrabi Zuri Zalla is the official Hondarrabi Zuri, and is the same as a French grape called Courbu Blanc.  Somewhat confusingly, there is also a grape called Hondarrabi Zuri Zerratia, which is the French grape Petit Courbu.  These two grapes (Courbu Blanc and Petit Courbu) are related to one another but are ultimately different cultivars.  The last email I have from Dr. Ortiz states unequivocally that the grape that is known officially as Hondarrabi Zuri is actually Courbu Blanc.

At virtually the same time, I received an email from Dr. Vouillamoz who had just read through my correspondence with Dr. Ortiz.  He had reached the same conclusion and believed that Hondarrabi Zuri was the same as Courbu Blanc (though he insists on maintaining that, sometimes, Hondarrabi Zuri also refers to Noah, which is true in a scientific sense if not a practical one).  Both the French and the Spanish Wikipedia entries for Txacoli seem to agree, as they equate Hondarrabi Zuri with Courbu (which can refer either to Courbu Blanc or Petit Courbu, but in this case clearly refers to Courbu Blanc).

The OCW has amended their entry on Hondarrabi since I emailed them a week ago.  The entry currently reads:

"DNA profiling has surprisingly shown that some vines of Hondarrabi Zuri are the same as the American hybrid Noah although the situation is particularly confusing because the name Hondarrabi Zuri is also used locally to refer to two other unrelated varieties: Crouchen and Courbu Blanc."


I've emailed them with the information that I have found, and they are sticking with their entry as it is written above, despite the fact that two different scientists have confirmed that the grape commonly referred to as Hondarrabi Zuri is, in fact, Courbu Blanc.  I'm reading this entry as saying that Hondarrabi Zuri is a distinct variety that is different from Courbu Blanc and Crouchen, but which is not related to either, which doesn't seem to be right to me.  It is true that Hondarrabi Zuri is occasionally used to refer to the Crouchen grape in this region, which is not related to Courbu Blanc, and I suppose you could read the post that way if you were in a generous mood, but I believe that the entry as written is still wrong.

The OCW was cooperative in this case, but was utterly uncooperative in the case of Emerald Riesling.  As I mention in that post, when I questioned them about the information they had published, they merely told me that I had the incorrect information and that I would have to wait for the publication of their book (which retails at a whopping $125) to find out what the truth actually is.  I would be fine with this if I wasn't already paying (dearly and annually, I might add) for the electronic version of the OCW, which they are coyly updating on the fly as they find new information, whether it is correct or not.  If I were paying for an online version of the book I also have on my shelf at home, that's one thing, as static reference materials go out of date all the time.  But since they are updating the work online, it doesn't seem unreasonable to ask for clarification on a matter where the information that they are printing is in opposition to every other resource currently available, including a written statement from the man who created the grape himself.  The OCW is a valuable resource, but they're not infallible, as I hope I've shown in this post.  If you are going to charge people for access to information, I feel that you should be prepared to justify that information if asked and should not point them to another place where they can give you more money for the whole story.  If you're willing to publish part of the story in the OCW and take people's money for it, you should be willing to publish the whole story instead of using premium content as a teaser for more premium content.  I don't subscribe to the OCW to read part of a story, and I'm starting to question whether I should be subscribing to it at all.

**UPDATE**

I've written much more about the Emerald Riesling issue in this post.

SOURCES

Ibanez, J., de Andrea, M.T., Molino, A., & Borrego, J.  "Genetic Study of Key Spanish Grapevine Varieties Using Microsatellite Analysis."  American Journal of Enology and Viticulture (54:1).  2003.  22-30.

Martin, J.P., Borrego, J., Cabello, F., & Ortiz, J.M.  "Characterization of Spanish Grapevine Cultivar Diversity Using Sequence-Tagged Microsatellite Site Markers."  Genome (46).  2003.  10-18.