The simple chemistry behind removing wine sulfites

There’s something horrifying about our standard reaction to a food label reading “Contains X” being “Is X bad?” That appears to be the standard reaction to sulfite labeling on wines: they had to tell me it’s there, so it must be bad for me. But it would be unfair of me to harp too much on snap judgments when I feel so much instant distrust toward Üllo just because they brand themselves with this horribly stereotyped photo of four young, attractive entrepreneurs smiling broadly at each other over their glasses.

Üllo promises to take any wine that comes with a “contains sulfites” label and turn it into a kinder, gentler, sulfite-free beverage. (Pardon the irony, but I’m still getting over that photo, and their name.) Just to cover my bases, once again, if you react to sulfites, you react to a lot of foods other than wine, you’re probably a severe asthmatic, and you’ll know. There’s nothing wrong with a tool to remove sulfites per se, but it contributes to this whole myth of their being a good reason why the Ordinary Wine Consumer would want to.

The scientific principle at work here is simple, and Üllo is a miniature version of a tool chemists and biochemists use often. In a complex mixture of many different molecules, some molecules will be selectively attracted to each other on account of unique properties related to their electric charge, shape, and atomic composition. If you want to remove one specific molecule or type of molecule from a mixture, you can pour the mixture through a resin loaded with another molecule that attracts it. Your Favorite Molecule (YFM; or least favorite, if we’re talking about sulfites) will remain trapped in the resin while everything else in the mix falls right through.*

What the Üllo folk did was come up with a “food grade polymer” that uses this principle to trap sulfites and put it in this thingamajig that you can sit over your wine glass. Once all of the polymer molecules are loaded up with sulfite molecules they can’t bind to any more, which is why the little filter that sits in the Üllo cup is disposable. They probably needed to do a lot of tinkering to find precisely the right polymer, so kudos to them on that account.

There are two problems with this simple idea. The first is that it’s not perfect. Some of YFM will always miss being bound up and fall through. Üllo marketing deals with that by talking about “returning” wine to it’s “natural” state, and since yeast naturally produce some sulfites, that leaves them about 10 ppm (parts per million) wiggle room. If you’re one of those rare few with a bona fide sulfite problem, that probably isn’t enough to set you off, though individuals’ sensitivities vary.

The second problem is the converse of the first. Inevitably, some stuff other than the target molecule gets stuck on its way through the filter. Üllo is trying to turn this bug into a feature by noting that you’ll remove unwanted sediment as well as sulfites, though I’d hazard that very few people in the target audience for this product are drinking wines with unpleasant sediments in the first place. I’ve not tried Üllo, so I don’t know how wine tastes after being poured through, nor what besides the sulfites changes in its molecular profile. But no matter how good a job those smiling entrepreneurs did with their chemistry, the wine will sustain some collateral damage. Again, probably not a problem if you’re drinking a commercial wine product to have something to hold at a party, but an altogether different issue if you’re expecting to savor the winemaker-crafted nuance of something special.

Üllo is a clever idea: simple, obvious, the kind of thing that makes you wonder why no one’s thought of it before. It might be a great tool for the gluten-avoiding Yellow Tail-sipping crowd that will feel better knowing their wine is virtually sulfite-free. It may even be a real help to some of those very few people who want to drink sulfite-containing wine but can’t breathe when they do. My problem with it is precisely the same as with gluten-free products. Most people don’t need them. Some of those folk are fooled into thinking gluten-free products are healthier anyway (even though they’re often lower in fiber and sometimes higher in fat and sugar). And while some of them are fantastic, most aren’t, and you’re usually losing something else along the way.

*The point of this exercise is often that you want to recapture a purified version of Your Favorite Molecule (YFM), so separation columns are often designed to be reversible: if you pour a solution of something that binds to the resin even better than YFM, YFM will fall off and come out the other side. When I spent time in a biochem lab working on HIV proteins, we used this technique to isolate specific viral proteins so that we could subject them to more testing.

April 2017:  I’m no longer accepting comments on this post after an ongoing deluge (relatively speaking, I know) of comments on this post telling me that I’m not taking individual’s symptoms seriously. Please note that I’m not telling anyone that their symptoms aren’t real or that they shouldn’t do things that make them feel better. I am saying (in addition to observing the clever chemical principle at work here) is that the best evidence we have at present suggests that sulfite allergies are very rare, and that this product preys on the same notions at the heart of the gluten-free craze: that a molecule which causes a very few people extreme harm is also somehow something the rest of us should fear.

The National Science Foundation’s new policy means better wine research access (and maybe just better research)

Last week, the National Science Foundation (NSF) announced that any journal article published as a result of funding issued from its coffers must be made freely available to everyone. The policy goes into effect for papers published in and after January 2016. Let’s get the two caveats out of the way first:

  1. Articles must be made available within 12 months of publication, so SAGE and Elsevier and the rest of the journal hogs (I’d prefer to use stronger language) have a year’s space for embargo policies. (Though there’s already work to make this 6 rather than 12 months.)
  2. The NSF won’t (for now, at least) compile it’s own article archive. They’ll have a database of titles and authors and abstracts and such with links to full-text articles available on publishers’ websites. That’s cheaper in the short term but less than ideal: different journals’ formats will make collecting “big data” sort of information harder, and we’re still tied to those journal hogs.

This is still a good thing. Between this and similar policies at the other major U.S. funding agencies (the National Institutes of Health did this, plus creating their own archive in PubMedCentral, in 2008), the published results of essentially any research project funded at least partially by the American government belong to everyone, worldwide. A good example of NSF-funded wine-related research is California-based work on the glassy winged-sharpshooter. Hardly mitigates the harm our government has done to the world, but it’s nice, and it makes the slope toward information being shared freely for everyone’s benefit a little slipperier.

Many wine industry folk look to Google for technical information and browse what surfaces pretty omnivorously, reading reports in trade journals, scientific articles or their abstracts, agricultural news, other farmers’ blogs…so long as it doesn’t end in .porn or seem to be published by a puppy mill in a third-world country, it’s probably at least worth a look. That said, some sources are more reputable than others and some of the most reputable are the most inaccessible: unless you’re a student or staff member at a tertiary educational institute, or unless your sugar-daddy parent company buys a subscription to AJEV, you’ll only see one-paragraph summaries (abstracts) of scientific articles.

The new NSF policy helps change that. Not all American wine research receives government funding, and countries such as Australia and New Zealand still think that research resources should be walled off just to their domestic levy-payers. The EU has exhorted it’s member countries to implement “European-level open access,” but maybe they’ll eventually care that this isn’t doing global social justice any good. Still, this means that winemakers’ (and everyone’s) Google searches will now lead to more full-blown studies with methods and detailed results and all of those other useful middle bits not encapsulated in the one-paragraph summary.

I think that open access will do more than just make it easier for everyday non-academics to see journal articles. I think that this will change the way scientists interact with the “end users” of research and, maybe, eventually, how those journal articles are written. Let’s say that you’re a winemaker trying to learn more about bacteria and soil health (already open-access thanks to the Department of Energy’s policy). You search for key words, find and read an interesting-sounding article, and have a question. You can, if you’ve got gumption, email one of the scientist-authors to ask it. And since most scientists are nice-but-busy people who want their work to matter to someone, you have a decent chance of seeing a reply.

In other words, the audience for scientific publications — especially for applied, industry-relevant research — is getting bigger. As it does, scientists may begin thinking about writing conclusions that acknowledge the interests of those non-scientists, and writing more clearly, and helping everyone — scientists included — see and make better connections between bitty research findings and the bigger world. That’s the real purpose of scientific research — to doodle in the blank spaces on the shared knowledge map of humanity. Open access helps.

How to replicate a wine from 1500 year-old grape seeds

*October 27, 2015 update: This post won the 2015 Born Digital Wine Award for “Best Investigative/Journalistic Wine Story.”

How to replicate a 1500 year-old Negev wine: 

  1. Unearth 1500 year-old grape seeds from the famed Byzantine-era city Halutza. (Done; credit Israeli archaeologists.)
  2. Extract DNA; sequence. (This is the easy part.)
  3. Check sequence against known contemporary grape genomes (to infer evolutionary relationships, and to double-check that seeds really weren’t refuse from archeologist’s lunch before proceeding).
  4. Realize that DNA sequence from seeds doesn’t represent DNA sequence of original cultivated vines, because Vitis species are notoriously mutation-prone. Halutza vignerons would probably have worked with grafted vines and selected varieties the way we do now (cf. Theophrastus who wrote about grafting in Athens in the 3rd c. B.C.). Deal, because we can infer a lot about the parent vine from the seed DNA but the stuff we can’t infer can definitely change wine quality (cf. reason why every contemporary commercial grapevine is propagated by cutting and not from seed).
  5. Synthesize fresh, lab-manufactured DNA from the old sequence (there are companies for this).
  6. Get someone like Dr. Andy Walker at UC Davis to (get his grad students to) clone new DNA into grape stem cells.
  7. Plant lots of babies. Watch lots of them die. Wait.
  8. Try to find a climate similar to c. 500 AD Halutza for vine cultivation (consult archeological meteorologist?) Hope that soil types also have something in common, or try to replicate historically appropriate soil.
  9. Accept that since grapes are subject to lots of somatic mutations, the new grape vines may change a bit along the way and not be exactly like the original Negev wines. Keep dealing.
  10. Consult Dr. Patrick McGovern (biomolecular archaeologist specializing in fermented beverages; Dogfish Head collaborator/co-creator of Midas’s Touch, etc.; outstandingly nifty person) about mimicking historical winemaking. Do what he says.
  11. Hope that Dr. McGovern has advice on how to handle the problem of modern Saccharomyces cerevisiae being a darn sight different than whatever might have been around to ferment things in the Byzantine Negev.
  12. Option A: Backtrack 15-20 years and clone person using DNA from bones found at Halutza dig. Raise in a bubble (consult designers of The Truman Show) to mimic growing up in Byzantine Halutza. Make sure he doesn’t try any wine until the replicated stuff is ready, then get him to write tasting notes. Option B: Accept that even if we’ve perfectly replicated an ancient wine (see above caveats about genetic variation, yeast, etc), we won’t actually have replicated the wine because we, the drinkers, will be different, and the wine only fully exists in its drinking and enjoying via the participation of complex sensory and thinking apparatus attached to a subjective human being.
  13. Drink the darn wine anyway. Invite Robin Trento over to make dinner (ask her to bring her own garum). Look up retirement residence addresses for the journalists who were “ready for a taste of the Byzantine Empire’s favorite wine” back in 2015 and make sure they get a bottle.