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California's Newest Grape Varieties are PD-resistant - Are They Consumer Friendly?

What UC Davis's recent research offers the grape growing community may differ from the wine market's demand.
by Curtis Phillips
December 20, 2019

I have known, for some years, about the development of several new grape varieties being bred by Andy Walker at UC Davis. Five of the cultivars were officially released on Dec. 18, 2019. The five cultivars are all patent pending and have been named Camminare Noir, Paseante Noir, Errante Noir, Ambulo Blanc and Caminante Blanc.

Errante Noir

All these new varieties were created by breeding Vitis vinifera cultivars with Vitis arizonica, and then (this is the really important part) selecting the children that inherited resistance to Pierce Disease (PD) from V. arizonica and breeding them back with V. vinifera multiple times, selecting for PD resistance each time, until the descendent grapevine is resistant to PD and 97 percent V. vinifera, in the case of Paseante Noir, Errante Noir, Ambulo Blanc and Caminante Blanc. Camminare Noir is 94 percent V. vinifera, and resistant to PD.

These new grapevine cultivars represent a monumental grape breeding project that took more than 20 years to accomplish. The project was only able to have vines to release in 20 years time because modern DNA analysis is able to spot if a seedling has a given gene, in this case gene(s) conferring PD resistance, immediately without having to spend 10 to 20 years growing each generation to see if it is susceptible to PD.

I don't want to underplay the accomplishment that these five varieties represent. All five cultivars may be the only hope for viticultural areas like Temecula that have heavy PD pressure, especially over the long term. All the same, I fear that the U.S. wine industry is not up to the task of adopting them.

If we take the entire U.S. wine market for varietally labelled wines as being represented by a single case, then six of those 12 bottles are Chardonnay, three are Merlot, one is Cabernet Sauvignon. One of the remaining two bottles is roughly half Pinot Noir, one-third Zinfandel, and one-sixth Sauvignon Blanc. Every other varietal is represented by that last bottle. This is the corner in to which we have painted ourselves.

I am concerned about the overall economic success of these varieties in a wine market where any wine not labelled Merlot, Cabernet Sauvignon or Chardonnay struggles to find its niche. If the consumer is looking for something other than Merlot, Cabernet Sauvignon, Chardonnay, Pinot Noir, Zinfandel or Sauvignon Blanc, that consumer is by definition not a typical wine consumer. I fear that the wines made from any of these newly bred varieties will either have to be hand-sold out of the cellar door, thereby severely curtailing the success of the varieties, or will have to be sold without the grape names listed on the label, either as generic wines or as a small percentage of a wine sold as a different varietal.

I am also concerned that without a sufficient number of vineyards growing these cultivars and wineries and winemakers making wine from these cultivars, we won't ever figure out how to get the best from them. In my opinion, even well established, but fringe "new" cultivars. like Carnelian, Ruby Cabernet, Symphony or Flora haven't been fully explored as varietal wines. Sure, there is a lot of Ruby Cabernet and Rubired produced in California, but when was the last time one encountered a bottle of Carnelian? Would a supermarket shopper pick one up, or have we done too thorough a job scaring them away from picking up anything out of the ordinary?

The onus for this is on us. Andy Walker has done an amazing job breeding PD resistance into these cultivars. It is now our job to figure out how to make great wines from them or they, and perhaps the California wine industry, will be consigned to the dustbin of history.

The press releases from UCD regarding these cultivars may be found here and here.

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