On the joys and sorrows of rising cabernet sauvignon in Washington State

Booming cabernet sauvignon plantings in Washington State have made wine news this past week following a new report from the United States Department of Agriculture’s National Agricultural Statistics Service. This news makes me sad, though I probably shouldn’t be.

Washington can do superbly good things with cab sauv. Even if some efforts are built for earning high points from Wine Spectator rather than actual drinking enjoyment, Red Mountain and its neighboring AVAs in the state’s southeast can turn out beautifully dense, velvety, complex cabernets that make you want to pull out the good china for dinner. And cab sauv gives strength and seriousness to the red blends that are, across the board, what southeastern Washington does best.

Back In 2014, I wrote a piece for Palate Press inelegantly titled “When your iconic wine is everything: Washington’s diversity issue.” I had just returned to New Zealand from a fieldwork visit to my old home state, where I’d reveled in good bread, central heating, people who didn’t want me to taste multiple sauvignon blancs in a row, and plenty of really excellent wine. In that context, I’d been struck by the extent to which neither Washington State nor any of its subregions had One Big Wine that made up their public identity. New Zealand immediately conjures up Marlborough sauvignon blanc, Central Otago pinot noir, and Hawke’s Bay syrah. In the States, most readily nameable “regions,” whether states or American Viticultural Areas, have an equivalent: Napa cab, Oregon (Willamette Valley) pinot noir, Finger Lakes riesling, even Virginia cab franc and Missouri Norton. All grow other things, and in particular I’m sorry that Central Otago isn’t better known for its aromatic whites and that Marlborough isn’t in a position to develop its promising chardonnay and pinot noir. Nevertheless, the iconic wine is what consumers latch onto, what makes the region memorable and easy to understand, and what sells.

Washington doesn’t (yet) have an equivalent. (Red Mountain is known for cab sauv and Walla Walla for merlot, but only regionally as yet.) The state’s diversity doesn’t help it when a nervous New York City restaurant diner just wants to choose something familiar. Moreover, the best wines being produced in Washington are cab sauv, merlot, or blends driven by those grapes. If New York noshers are going to recognize not just Washington but Red Mountain, Walla Walla, and Horse Heaven Hills, big reds will be the reason.

But the best wines don’t always make for the best drinking. Diversity makes for a joy-provoking field to explore if you’re willing to get to know them, and a welcome tasting experience if you’re out for the day. Washington winemakers – most of them running tiny businesses by California standards – to their credit, aren’t afraid to experiment in their still relatively young terrain and to find varieties outside the big 6 that are worth both their time and yours.

Not all of those experiments need to become traditions, and some no doubt deserve to be planted over with cab sauv. But some of those unusual wines are brilliant, from the totally unexpected and thoroughly delicious montepulciano I once tasted in the winemaker’s garage to the creamy semillons more often offered alongside those big reds – but, the numbers suggest, increasingly being edged out by cab sauv. These trends are signs of the state’s wine industry growing up. They’re also signs, perhaps, of losing something unique and beautiful the state losing a big part of what makes it unique, worthwhile, and beautiful to someone who isn’t nervously noshing in New York.

There’s much more to be said about the interactions of developing an icon style with winery size, consumer expectations for consistency, brand associations with wine labels or wine regions, climate change, fashion, distribution, and the development of new AVAs, among other things (some of which I say here). All topics that I hope the industry is discussing, and discussions that I hope to see taken up more publicly as well. For now, it seems that what I really want to say is: three cheers for odd-ball wines, in Washington and elsewhere.

Effects of grapevine leafroll disease on wine quality (and when is a disease a disease?)

Gut reaction: Viruses cause disease. Disease is bad. Viruses are bad.

Gut reaction muted by a lot of recent genetics research: Viral DNA seems to be embedded in genomes all over the place. We’re not sure why a lot of it is there, or stayed there, or what it does while its there. Some viruses cause disease. Some don’t. Viruses are complex, and we probably don’t know the half of it yet.

A name like “grapevine leafroll-associated virus” gets you thinking about negative consequences. Rolled leaves don’t collect light efficiently, which means that they won’t contribute to the plant’s photosynthetic metabolism efficiently, which means that the plant may be malnourished, grow slowly, and/or not have enough energy to ripen fruit. Rolled leaves are bad. A virus that’s associated with rolled leaves is bad. But the virus is only associated, not causative. Some viruses in this general family of leafroll-associatedness aren’t associated with vine symptoms. And infected vines only show symptoms post-veraison (the stage of ripening at which grapes change color), even though they carry the virus in detectable quantities year-round.

Ergo, a group of vine and wine scientists headquartered in eastern Washington state designed an experiment to ask (published in PLOSOne, and therefore open-access to everyone): do grapes from vines with grapevine leafroll disease, and carrying one of these viruses (GLRaV-3), lag behind their undiseased counterparts throughout ripening, or only when vines show symptoms? Being particularly conscientious*, they also improved on existing studies of grapevine leafroll disease by collecting data for three consecutive years from a commercial vineyard, sampling grapes throughout the season but also harvesting grapes at the typical time and making wine from diseased and undiseased pairs, and subjecting those wines to (limited) chemical and sensory analysis. They also used own-rooted rather than grafted vines, which eliminates some potentially confounding variables.

Their conclusions, after collecting data over the 2009, 2010, and 2011 growing seasons:

  • Grapevine leafroll disease decreases vigor (as measured by cane pruning weights) and fruit yield in own-rooted Merlot vines in Western Washington.
  • Grapes from diseased/infected vines have lower total soluble solids (TSS) and higher titratable acidities (TA) (and, to a less dramatic degree, lower anthocyanin concentrations) than grapes from undiseased/uninfected vines, but only after vines begin displaying symptoms post-veraison.
  • Wines made from diseased grapes were browner and less intensely colored, earthier and less fruity, and more astringent compared with their undiseased counterparts.
  • However, panelists only correctly distinguished diseased from undiseased wines when served side-by-side in black glasses, removing the notable color differences from consideration and forcing them to differentiate on smell and taste alone.
  • Soluble solids, TA, and pH were all more dramatically affected than anthocyanins in diseased vines, which reflects the decoupling of anthocyanin development and sugar accumulation that happens late in ripening during which environmental conditions play heavy in anthocyanin development.

These conclusions probably do more for plant scientists than for commercial growers: data from one Merlot vineyard near Prosser can’t be precisely extrapolated to you, wherever you are, and thresholds for usable fruit are always a matter of context (the authors note that future studies should document the effects of grapevine leafroll disease on specific sensorily-important compounds). The study does add data points to a collection of statistically robust data that might help large companies make judgments about what they can include in their generic red blends before pH or some other parameter becomes a problem. But maybe the most interesting line of thinking here has to do with the nature of disease, and of relationships between viruses and diseases and symptoms. Do vines have leafroll disease before they exhibit symptoms? Where do we want to draw lines between normal or acceptable variation and disease symptoms? If a vine looks sad but makes grapes that make wine indistinguishable from happy-vine wine, and if genetic testing says that the plant also happens to have a virus, does that mean that the vine has a disease, or is it healthy?

Disease” can mean something different to the plant pathologist who looks at a vine, a geneticist who looks at the DNA of a vine, a commercial grower who looks at the fruit of the vine or a winemaker who looks at the juice it makes. That vine may be infected with viruses. Is the virus bad?

 

*Full disclosure: I know and think highly of several of the scientists on this team.

Spice and sulfur: Recent research news from Australia

Wine Australia’s “research, development, and extension” arm periodically releases briefings on research they’re funding. This month, two of those briefings promise particular interest for folks outside Oz.

Spice (Rotundone)

Short: How rotundone (and the peppery flavors it yields) develops in grapes still lacks good scientific explanations, but scientists are working on it and suspect that it’s a multi-factorial process involving sunlight and air exposure as well as enzymes.

Longer: Not necessarily positive for wine quality, but stellar for talking about how chemistry produces flavor. Rotundone is the “impact compound” behind the peppery flavors prominent in some Australian shiraz (and some other red wines), and rarely does a single compound correlate so clearly with a single and very easily identifiable wine sensory note. The sensory correlation seems simple (caveat emptor: expect it to become more complicated as scientists spend time studying it). How rotundone forms is anything but. A lot of scientific activity (and not just in Australia) over the past year or so has been working out both the chemical pathway (enzymes and intermediates) responsible for rotundone and the viticultural parameters describing where it forms.

A major rotundone conundrum has been why its concentrations seem highest in cooler sites – within the plant, the vineyard, and a region – and yet rotundone characterizes ripe Australian grapes. As is so often the case in scientific conundrums, the confusion may stem from trying to pin causality on the wrong set of variables. Rotundone is formed by an oxidation reaction. Recent work says that that oxidation may be motivated by enzymes, sunlight, or oxygen. Or all three. And so, even if rotundone = peppery flavors is a simple equation, solving X + Y + Z = rotundone is shaping up to be a good deal more complicated.

Expect big rotundone news from Australia in upcoming years. Sussing out a viticultural recipe for maximizing (or minimizing) pepper flavors in shiraz could set up Australian shiraz to do what the Marlborough sauvignon blanc industry has done, creating an international brand around a distinctive flavor profile, fueled by scientific research into how to make those flavors ever more obvious. What that research means for smaller producers who aren’t aiming for those sorts of flavor profiles is a different, and interesting question. 

Sulfur (and copper)

Short: Adding copper to finished wines to remove or prevent sulfur aromas may not work the way everyone hopes it does.

Longer: Wines made with very little oxygen exposure and bottled under screw cap don’t have much chance to blow off smelly sulfur compounds produced via this sort of reductive winemaking. (Why sulfurous aromas are a problem in reductive winemaking involves some complex microbiology that’s summarized well here.) A standard prophylactic against eau de cabbage or rotten egg in your freshly unscrewed bottle is adding some copper before bottling; copper binds to the smelly sulfur compounds and acts as a heavy anchor of sorts, keeping the malodorous molecules from volatilizing, entering sniffable air space, and registering as an undesirable aroma. Adding a copper penny to a sulfurous wine glass is a common parlor trick for confirming that particular wine fault; if you’re really smelling sulfur, in theory, the penny should mitigate the problem.

A nice, simple solution to nasty sulfur aromas would seem to be adding copper to bind to and “lock away” sulfur compounds, then counting on pre-bottling filtering to remove the copper-sulfur compounds.

Problem #1: It seems that filtering doesn’t reliably remove the copper.

Problem #2: The copper-sulfur binding isn’t always stable or permanent, so the copper may go off and do other (undesirable) stuff no one was counting on.

It seems likely that copper additions are useful under some if not all circumstances. The future work – of researchers and winemakers working together, one hopes – is defining “some if not all circumstances” more precisely.