Does cross-flow filtration affect wine flavor? No easy answers.

Cloudy wine (mostly) doesn’t sell. Neither does (most) wine spoiled by spoilage microbes that produce off-aromas. And so, while it is entirely possible to remove floating particles that make wine cloudy and (most) microorganisms via careful winemaking without sterile filtration, most winemakers appreciate the extra insurance it gives. Filters are essentially membranes punctuated by lots of little pores: all good stuff should flow through the pores; bad stuff you want to keep out of the bottle should be too big to pass. To reliably remove yeast and bacteria, filters need to have really tiny pores, and the question always is: are those filters excluding stuff other than the microbes, good-tasting stuff that I want the wine to keep? We’re talking .45 μm pores here, an order of magnitude smaller than the diameter of a red blood cell; anything bigger risks allowing bitsy bacteria through.

Pro-filtration folks say that all molecules important to wine quality are much to small to get caught in even these super-stringent filters. Filtration-shy folks say that wine tastes different post-filtration; no matter what molecular measurements say should happen, something is happening. For an excellent discussion of the arguments on both sides, see Tim Patterson’s excellent review in Wines and Vines (updated here, but this one is still behind a pay wall). Bottom line: scientific evidence suggests that while some important molecules could get stuck to the surface of the filter, all the important stuff can pass through safely; dissenters can still taste a difference, and maybe that has something to do with big conglomerates of molecules.

So it stands for conventional filtration. But what about cross-flow filtration, they shiny new-ish solution to some of the conventional process’s major hassles? Conventional filtration points a stream of flowing wine directly at the filter membrane and waits for it to percolate. Enough push needs to be behind that wine stream to keep things moving, but too much push and the force of the flowing wine will rip right through the filter. And the wine must be almost entirely free of particles in the first place, else biggish stuff will cover the surface of the filter, block the holes, and slow down flow. Either way, the filter membrane will need to be replaced, and they’re expensive. Cross-flow filtration instead points the wine stream across the surface of the membrane. Liquid still flows through but with less direct pressure on the membrane, and the constant stream sweeps pores clean of junk, too.

So cross-flow is better than traditional filtration for a few technical reasons. Is it also better for wine quality?

A study addressing that question has just been published (as a provisional draft; it’s not yet appeared in the print journal) with work done by a team from UC Davis. A few published articles have shown chemical analyses of cross flow-filtered wines, but this study is unique and helpful in two ways: 1. The emphasis was on whether a trained tasting panel could detect flavor differences in filtered wine; and 2. Wines were tested not just immediately after being filtered, but from bottle samples taken at intervals out to eight months post-filtration. Kitchen-sink white and red blends were included.

Though the group’s experiments aimed at looking for sensory differences following filtration, their results uncovered something else. The flavor of the unfiltered red wine changed more over time — more earth, less fruit beginning at two months and continuing to the eight-month end point – while the flavor of the filtered red remained more or less constant; in other words, the filtered wine was more stable. The obvious explanation is that the unfiltered wine suffered from some kind of microbial growth after bottling, even though the idea of a UC Davis-crafted experimental wine having microbial spoilage issues does seem strange.

More to the original point: even though chemical analyses showed that filtration decreased phenolics in the wine — filtered reds had lower pigmentation and up to 26% lower tannin levels — the tasting panel didn’t pick up corresponding differences in astringency. That’s surprising. The only explanation offered in the paper is that the magnitude of the change mustn’t have been big enough to be detectable.

In the end, then, this study probably does more to fuel the filtration debate than to help resolve it. Pro-filtration folk can point to filtration’s apparent lack of sensory impact, and to the likely spoilage of the unfiltered wine. Filtration-caution folk can point to the color and tannin changes and say that, even if those changes didn’t affect flavor in this wine, similar changes might indeed be important in other wines. So instead, we have one more example of what may indeed be Rule No. 1 in winemaking: there are no easy answers.

Why playing music to wine may not be a cockamamie idea

When is a train like a jazz tune? When someone tries using them to improve wine quality. Recently, Wine-Searcher ran a piece on Juan Ledesma, a Chilean winemaker using waterproof speakers submerged in the barrel to – infuse? – his malbec and cabernet as they age. If you believe that some kind of spirit inheres in all living things even through their killed and processed forms, and also believe that music has spiritual effects, then it might also be logical for you to believe that music has some kind of metaphysical effect on wine that transmutes through its spirit into its physical form, affecting both the taste of the wine and, perhaps, the spirit of the person who consumes it. Fair enough logic. But when I think about music, I think about trains. Trains and music, both, are sources of vibrations which at least theoretically affect on wine quality. What kind of an effect has been a matter of speculation and maybe a little superstition or wishful thinking, but not much research. A few years ago, a winemaker contacted me to ask whether his barrel room being under a railway overpass – and, consequently, being subject to the rumbling vibrations of frequent passing trains – might have some kind of softening effect on the tannins in his reds. Had he consulted what turns out to be a century-long history of winemaker interest in train-derived rumblings, from  he would have found as much or more worry about negative effects as positive. His spiritual predecessors, 1920′s London wine merchants, hoped that their wines stored in barrel under the city’s railway arches would mature faster and to good effect. Sixty years later, a great vinous uproar occurred when the French government proposed a new TGV route to transgress Vouvray in the late 1980′s, not only for fear that vineyards might be destroyed but that vibrations from the train might disrupt cellaring wine. (The not-entirely-equitable solution: a tunnel under the vineyards and anti-vibration mats under the tracks.) The TGV folk purportedly did their own research and found that passing trains had no effect on wine quality, but they never published any details from their studies. Playing music to wine could be dismissed as new-aged nonsense and worrying about trains as old-timer technology resistance. But, both trains and music are sources of vibrations. Vibrations may not make wine “mature” faster, but they could do something. The obvious effect of vibration, at least on wine being aged before fining and filtering, is in stirring up lees. Sound vibrations jostle and stir up wine a bit — just a little, but enough perhaps to keep dead yeast cells that would settle to the bottom of an unjostled tank stirred up and suspended in the wine a bit longer. Interaction with dead yeast cells — lees, when they collect at the bottom of a tank or barrel — changes wine quality: as yeast cells die and decay, they release a slew of interesting cellular leftovers. Some of these add directly to flavor, some give weight and richness to mouthfeel, some we certainly haven’t yet figured out. Increasing “must turbidity” — stirring up the wine — increases the amount of these yeasty components in the finished wine. To date, research on wine and music has involved how shoppers respond to in-store playlists (French music improves French wine sales, German music improves German wine sales) or how ambient music alters our sensory perceptions while tasting (people’s ratings of the weight and sophistication of the wine they drank tended to match the weight and sophistication of the music they heard). We’ve yet to see research on playing music to the wine rather than to the customer, though that looks to change as the Chilean Agricultural Innovation Fund has, the Wine-Searcher piece reports, invested in studying the wine-plus-music phenomenon. Regrettably, no indication from Amtrak that they plan to participate.

Tragon’s new closures report, transparency, and the marketing vs. science clash

Tragon, a consumer sensory testing firm based in San Francisco, just released the fourth installment of a study into how consumers feel about natural cork versus screw caps. Tragon conducted surveys in 2004, 2007, 2011, and 2013. The 2013 report shows that consumers are more accepting of screw caps than they’ve been in the past. Still, the bottom line is the same now as it was in 2004: people prefer natural cork, perceive cork-topped wines as higher quality, and think they’re more appropriate for fancy occasions. Those conclusions held true across the US, Germany, and Australia, though the Aussies see screw caps as being very nearly equal to cork in nearly all settings.

I have no trouble believing that the average wine buyer prefers cork and thinks that it’s classier. Aesthetics, tradition, and familiarity are important. Cork wins on all three accounts. Given the exact same wine under different closures, my experience as a human who interacts with other humans tells me that most wine geeks will choose the screw-capped option, most non-wine geeks the cork.

Here’s where I have a serious problem accepting Tragon’s report. At first glance, their study seems to show that the average-Jessica wine consumer cares more about closure type than where the wine came from or what variety it is. Really?

Maybe lots of people (non-locavore people) don’t look at country-of-origin because they just see the brand and label design without reading the fine print. But closure is more important than whether the wine is white or red? This is hard to believe. Do people go to the store saying “I’m looking for a wine with a cork” or “I’m looking for a wine with a screw cap” more often than “I’m looking for a red?”

It took me a few reads to realize that the problem is probably with how the survey questions were worded** The summary report says that closure beat out country of origin and color in “character importance.” That tells us nothing about what question consumers were actually asked, but let’s imagine that the survey item was something along the lines of “How important are the following characteristics in terms of telling  you about a wine’s quality? Rank in order of importance.”

Whether a wine is red or white isn’t at all important in telling me about its quality. Red wines aren’t always better than whites or vice-versa. Duh. Similarly, for country of origin, a wine from California or Italy or New Zealand can be either very high quality or very low quality; not helpful. But if you show average-Jessica wine consumer two identical bottles, one corked and one screw capped, she’ll identify the corked one as higher-quality.

Nomacorc, makers of the leading plastic cork-like closure, sponsored a study in 2012 that found that American consumers only care about closures when they cause a problem: when a wine is corked, when they have trouble opening the bottle, etc. Those results might appear to be at odds with the Tragon study, but I’m not sure they are.  The Nomacorc report says that consumers don’t think much about closures. The Tragon study asks people to think about closures, then asks them whether they think of corks or screw caps as higher-quality. 

I don’t watch basketball. If someone asks me whether I think about basketball, I’m going to say that I only think about basketball when I’m annoyed and inconvenienced by traffic created by a basketball game (anyone who’s been on the Washington State University Pullman campus on a Thursday game night can probably relate). But if someone gives me a list of basketball teams and tells me to rank them in quality, I’ll come up with some kind of list based on what I’ve overheard from friends and news reports.

Something still doesn’t quite compute here. Tragon’s report shows that price was the most important factor in “character importance” — sensibly enough — but that $10-15 wines were ranked higher in “character importance” than $15-20 or wines over $20. I’d expect perception of quality to increase steadily with price, but that’s not what the graph shows. If Tragon shared their methods and their data — if they published the survey itself and graphs documenting actual results instead of just the slick summary — we’d know how to understand their results.

But instead, since this is a private company doing research on behalf of Wine Vision — an industry conference in which Amorim, the world’s largest manufacturer of natural cork, is a major sponsor — we see only the highly polished conclusions. So instead of research that adds to global understanding, we have research that supports Amorim’s market position, just as the Nomacorc study supported Nomacorc’s market position. A shame.

My conclusions? One: surveys are always more complicated than they appear at first glance. Two: how we ask questions has an enormous effect on the answers we get. Three: when private companies don’t share the details of their study methods or data, misunderstanding follows. Four: I’m not sure that science and marketing must always be at odds (though, frankly, I think they probably are) but, when marketing means no transparency, science loses.

**Neither the public summary reports nor the Tragon “research methods” web pages (frustratingly rich in graphics and poor in information) give any details, so all of this is speculative.

On Palate Press: a practical take on biodynamics

My March column on Palate Press, up today, takes a look at the practical side of biodynamics as its happening in Central Otago.

I think that biodynamics can become — well, if not dangerous, then at least unproductive or ill-advised — when it is a proscriptive set of rules that must be followed for specious reasons. But when it’s used as a theory for understanding the farm ecoystem, a tool for listening to the environment and strengthening connections between man and the rest of it, then it’s just good farming. And a lifestyle choice: biodynamics is the way these winemaker-growers want to live. But who wouldn’t want to live surrounded by flowers and bees and good-smelling compost? Looks more appealing than wearing face masks and gloves to protect yourself from the chemicals you’re going to spray on plants that will produce something you’re going to eat.

Find the full article on Palate Press.

Let’s stop a bad thing from happening for a good reason: saving a historic California vineyard

In a classic case of a bad consequence to an otherwise-good idea, 14 acres of Californian vineyard planted in the 1880′s are at risk of being bulldozed in the course of environmental restoration.

The Environmental Impact Report on the Dutch Slough Tidal Marsh Restoration Project, which plans to restore 1178 acres of farmland to tidal marsh around the Sacramento-San Joaquin Delta, is currently open for comment. To sign a petition asking for a 14-acre exception for the historic Carignane vineyard, go here.

Reasons why this matters:

1. The vines and vineyard represent agricultural techniques (sustainable, non-irrigated farming) valuable as both a historical and a practical lesson.

2. Carignane vines used to be common in California, but are now rare. This vineyard is a living testament to what the pre-prohibition California wine industry looked like.

3. Viticulture researchers look at grape genetics to understand why vines work the way they do and how we can make them work better. Jim Wolpert, the preeminent California viticulturist, argued that these vines represent a unique and useful source of grape genetic material in the letter he wrote to the project directors. Once that material is gone, it’s gone.

The petition organizers have compiled a much longer and more detailed list of reasons to preserve the vineyard.

The Tidal Marsh Restoration Project is, on the whole, a really excellent thing. 1178 acres of fields bordering Oakley that would otherwise have been turned into asphalt and concrete instead being turned into tidal marsh — wetlands where streams and rivers meet the sea — with adjacent “shaded channels, native grasslands, and riparian forests,” according to the project description. If you live in a coastal state, you probably toured a tidal marsh as a school kid; they’re incredible habitats for all manner of birds and fish and amphibians and insects and what-not (your teacher may have called it an estuary; they’re overlapping categories). The Environmental Protection Agency says that tidal marshes even help regulate water flow during drought-flood cycles because they’re big, flattish spaces that tolerate a lot of water rising and falling. Bacteria in marshes improve water quality by processing fertilizer run-off, too.

All of this is great for local native wildlife, increasingly being pushed out — and let’s be blunt about it: killed and threatened with extinction — when developers build fancy high-rises over their habitats.

BUT: 14 acres in the middle of this area-to-be-restored contain some of the oldest vines in California. Those vines are irreplaceable. We can conserve the vines and otherwise proceed with the restoration project.

Saving the vineyard isn’t about the wine industry versus environmentalism. This isn’t about money. It’s about the value of conserving history, about recognizing that historic vineyards merit the same consideration as historic buildings and other monuments, and about not doing irreversible things today that we’re going to regret in the future. I’d encourage you to sign the petition, send a comment to Patty Finfrock at Patricia.Finfrock@water.ca.gov, and help stop a bad thing from happening for a good reason.

Felton Road’s low-tech precision winemaking

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Gareth King at Felton Road

“Precision viticulture” refers to a technology-laden mission to optimize and equalize grape quality at a local level, decreasing variability plot-by-plot, potentially even plant-by-plant. By collecting data on water use, vine vigor, temperature, soil conditions, and other parameters at multiple points across a vineyard, vignerons can understand how different areas of the vineyard are differing in their performance and, consequently, irrigate or fertilize or prune or harvest or what-have-you differently to suit. Affordable GPS systems, high-tech mapping with geographic information systems (GIS), and lots of spiffy little wireless sensors have made all of this possible and even reasonably practical for vineyards within the past several years (Australia’s national Commonwealth Scientific and Industrial Research Organisation has been notably pushing PV adoption in that country). Oddly enough, though, I hadn’t really thought about what an equivalent “precision winemaking” strategy might look like before a week or two ago.

A week or two ago I paid my first visit (of many, I expect) to Central Otago, New Zealand’s most southerly wine region, famous for pinot noir, Wild West-style scenery, and hordes of international backpackers. When I made arrangements to stop by Felton Road, I was warned that I wouldn’t be able to meet Blair Walter, the winemaker, because he planned to rack that day. (Rack = remove wine from one container to another, most often for the purpose of separating it from the lees, the dead yeast cells and other particles that collect at the bottom of the barrel or tank.)  When I learned how he was racking — he found a few minutes to come out and talk in between barrels — the first thing that came to mind was, “gosh, this sounds like precision winemaking.” If precision viticulture is approaching the vineyard on a vine-by-vine basis, then precision winemaking seems as though it should be approaching wine on a barrel-by-barrel basis. Far from technology-laden, though, Walter’s method is simple, elegant, and light on gadgetry.

Their pinot noir is made like this:

1. Crush grapes into stainless steel fermenter tanks. Ferment.

2. Press and transfer wine to barrel. Let wine sit in barrel until February (in Otago, that’s about ten months after harvest).

3. Rack wine off lees, out of barrel and into tanks.

4. Bottle.

Racking happens only once. Walter says that everything that comes out of the barrel during that single racking goes into the bottle. With that single control point before bottling, he sounds fairly obsessive about ensuring sure that he sees everything that comes out of those barrels. Unsurprisingly, he uses a Bulldog Pup, a clever little racking wand that  moves wine by positive displacement instead of active pumping. Positive displacement functionally pushes — “displaces” — the wine out of the barrel by filling the barrel with gas. The barrel is sealed save for a tube pushing the gas in and the tube letting the wine out so that pumping in gas increases the pressure inside the barrel; the wine has nowhere to go but out the exit tube. Bulldog Pups are far more gentle than any pump. They can also virtually eliminate oxygen exposure during racking when nitrogen or argon is used to do the pushing.

Neither of those is Walters’ main reason for using the Pup. He even uses plain-old forced atmospheric air, replete with oxygen, to push. After ten months undisturbed in barrel, the wine can use the oxygen exposure. His reason for racking this way is so that he can watch the wine as it comes up the tube (through a conveniently placed sight glass) and decide on a barrel-by-barrel basis what to leave behind. Bulldog Pups have a foot that will automatically shut off flow at a pre-set level: a winemaker can decide to leave four inches of lees in each barrel, set the foot appropriately, and then leave the cane to mind itself while his attention is elsewhere. Walters doesn’t automate, and the only person who racks is him.

Walters’ approach reminded me of what his colleague Gareth King, Felton Road’s viticulturist, said about how he practices precision viticulture. The man doesn’t seem to want for much, but when we encountered the harvest crew coming in from a morning vineyard walk, he said, “You know my best technology? They just walked past us.”

I can’t say what difference GPS sensors versus summer interns might make, but I can say that Felton Road’s pinots were among the best I tasted. Central Otago pinots can be a bit clunky, but Felton Road’s are texturally lighter and more elegant, with plenty of clean raspberry and strawberry aromas up front backed up with enough earthiness and tannins to keep things interesting. The 2012 Bannockburn and 2012 Cornish Point bottlings seemed to walk that balance of lightness and structure particularly well.

Precision viticulture is veritably new. It’s downright revolutionary, really, in terms of how it changes the way vignerons can think about vineyard management. But technology isn’t the only way to pay attention to details. The old-fashioned strategy of carefully and consistently observing what’s happening with individual vines isn’t an exact substitute for GPS-enabled water uptake meters: the technology is more precise and lets the vineyard manager put his eyes in a lot of different places at the same time — and collect data in his sleep or during family meals, which has to be a real boon. And I can imagine monitoring individual barrels with some kind of wireless oxygen sensor that can track and measure differences between how each barrel transmits oxygen — since every barrel is unique in this respect — and lets winemakers make corresponding individualized adjustments. No amount of careful personal attention could do that.

But Walters’ version of precision winemaking and King’s version of precision viticulture will serve as a good reminder for me every time I read a journal article or press release about some nifty new precision gadget. Some of the best technology comes on two legs.

And the winner for strangest wine experiment of the year goes to…

Research about the effect of wine on cancer is pretty common. Witness the slew of attention resveratrol has received for being, among other things — like the fountain of eternal youth or your key to firm skin with no injections — an anti-cancer agent. We also see plenty of epidemiological research: the population studies that say things like “moderate red wine drinkers are less likely to develop lung cancer.

How these studies work is easy to understand. Cancer-like cells grown in dishes are bathed in resveratrol-containing solutions and observed afterwards (in vitro = “in glass;” the dishes are more likely plastic these days, but the Romans didn’t have a word for plastic, gosh darn-it). Or whole organisms — mice, worms, humans — are fed resveratrol and observed afterwards (in vivo = “in the living”).

In the “I haven’t seen this before” file is an article released in preliminary form at Cancer Cell International a week or two ago that did things a bit differently. They bathed in vitro lung cancer cells in wine. Picture where your lungs are and where wine goes when you drink it. See the problem?

Wine per se never gets past your stomach. Just about everything we eat is broken down into component parts before being pulled out of the digestive tract and into the blood, with the indigestibles — things that can’t be broken down and transported into the blood, like the cellulose in plants — being left to exit the other end. Where and how a compound makes the move from digestion to blood depends on the compound. Polyphenols, the class of chemical which includes tannins and anthocyanins that give wine astringency and color, respectively, are mostly absorbed in the small intestines. Resveratrol** and alcohol are both fairly unusual in being absorbed directly across the mucous membranes in the mouth and pulled into the bloodstream, which explains why we get drunk so fast as well as why it makes sense to treat cancer cells directly with resveratrol.

Bathing cancer cells in wine is therefore a thing that will never, ever happen in your body. I suppose that cancer patients could be given red wine via an IV, putting it directly into the bloodstream where it would have direct access to cancer cells. Intuitively this seems like a bad idea, though I couldn’t say precisely why. I also don’t know if that’s what these scientists were getting at, or if this was just a “wonder what will happen if we try this” experiment.

It is interesting that very dilute red wine solutions — less than 1% — had specific anti-cancer effects. White wine was only effective at much higher doses – 2-5%. The effect (on specific signal transduction pathways; too complex to explain here) wasn’t the product just of resveratrol or alcohol; the authors haven’t yet figured out what specific wine components are responsible.

French hospitals include wine as part of patients’ regular diets, which I’ve always thought was a much more sensible attitude to nourishing recovery than the insipid and very non-alcoholic slop served up in most American hospitals. Sipping slowly on a glass of red is likely to do you more good than using it to tint your IV drip pink, though who knows? Maybe that is indeed the next thing.

 

**Because resveratrol is absorbed in the mouth, drinking wine is an excellent way to get it into your bloodstream: sipping gives it time to be absorbed. Swallowing a concentrated pill is a terrible mode of delivery. When it’s fast-tracked to the stomach — the pill bypasses those mouth membranes — very little resveratrol makes it out to where it can do any good. For a fantastic, if highly technical run-down of what we currently know about resveratrol, check out the micronutrient pages at the Linus Pauling Institute at Oregon State.

Gluten labelling and the American government’s problem with fermentation

The U.S. Alcohol and Tobacco Tax and Trade Bureau (TTB) has just issued a new ruling on gluten-free labels for alcoholic beverages. Alcoholic beverages made with gluten-containing grains can’t be labeled as gluten-free, no matter what kind of processing they undergo.  That means that “gluten-free” can only show up on beers and whiskeys made entirely from sorghum, rice, teff, or other gluten-free grains (and which aren’t then stored in barrels sealed with wheat paste, which is a real potential source of gluten in alcoholic beverages). The language on this point is surprisingly direct for a document mostly filled with legal jargon thicker than oatmeal stout.

The Food and Drug Administration (FDA)  issued rules in August 2013 saying that foods could be labeled “gluten-free” if they were either made without ingredients that contain gluten or with “an ingredient that is derived from a gluten-containing grain and that has been processed to remove gluten (e.g., wheat starch), if the use of that ingredient results in the presence of 20 parts per million (ppm) or more gluten in the food (i.e., 20 milligrams (mg) or more gluten per kilogram (kg) of food).” But this wording poses a problem for beer and grain-based distilled alcohols. What about whisky, made with gluten-containing grains that aren’t pre-processed to remove gluten but distilled such that gluten never makes it to the bottle?

FDA rules say that “Allowing the ‘gluten-free’ label claim on food whose ingredients have been processed to remove gluten, but not on food that has been processed to remove gluten helps ensure that the finished product has the lowest amount of gluten that is reasonably possible, and consistent with the use of specific manufacturing practices that can prevent gluten cross-contact situations.” And “food labeled gluten-free cannot be intentionally made with any amount of a gluten-containing grain (wheat, rye, barley, or their crossbred hybrids like triticale) or an ingredient derived from such grain that was not processed to remove gluten.”

The new TTB rules extend from those FDA rules. Labels with statements along the lines of “processed to remove gluten” are okay if the producer runs the drink through lab testing demonstrating that it contains less than 20 ppm gluten IF they also say one of the following on the label:

“Product fermented from grains containing gluten and [processed or
treated or crafted] to remove gluten. The gluten content of this product
cannot be verified, and this product may contain gluten.”

OR,

“This product was distilled from grains containing gluten, which
removed some or all of the gluten. The gluten content of this
product cannot be verified, and this product may contain gluten.”

AND explain in detail the process used to remove the gluten. Yeah, right.

The fundamental problem is that the FDA and the TTB don’t think that we have adequately proven detection tools for gluten in alcoholic beverages, and they have a point. There’s surprisingly little published research on detecting gluten in alcoholic beverages. A few studies demonstrate that we can detect gluten in conventional beer and in wines clarified with gluten (see Simonato et al. or Catteneo et al.), but I can’t find any published studies looking for gluten in distilled alcoholic beverages. This looks like a major gap in the literature.

That said, this labelling issue represents in some ways a much bigger problem that the FDA — and the American food regulatory apparatus in general — has with fermented foods of all kinds. We have excellent methods for detecting gluten in food and beverages generally. The FDA is perfectly fine with those methods applied to crackers, or soup, or anything other than “fermented and hydrolyzed foods.” But “fermented and hydrolyzed foods” are different, for some mysteriously unexplained reason.

The US government just doesn’t know what to do with ferments. FDA regulations about refrigeration and hygiene make restaurant foods deliberately left out to grow (beneficial) microbes illegal: house-made lacto-fermented sauerkraut or pickled beets or traditionally-prepared crème fraîche need to be quietly hidden under the table when the health inspector comes ’round. And when implementation of the new Food Safety Modernization Act — which requires that all food preparation facilities be inspected by FDA agents — made its way to wineries last year, inspectors accustomed to touring dairy plants told winemakers that cellar staff should wear hair nets, that crushing outside wasn’t okay because birds could poop onto the grapes, and that dogs weren’t allowed in wineries.

The antibiotic, antibacterial mainstream assumes that bugs are bad, and the government regulations aren’t smart enough to differentiate spoiled = bad from fermented = good. Fermentation culture patriarch Sandor Katz gave a lovely talk at MAD last year that touched on these issues. And thanks in no small part to people like Katz (really, thanks in no small part to Katz; the guy is a fermentation powerhouse, an icon for the movement, and one of my veritable heroes), foodie activists are fighting in small, quiet ways against the  bacteria-are-bad mainstream and building a strong counter-culture capable of recognizing that refrigeration is one of many good and useful ways of dealing with food. One of many, also including pickling by lactic fermentation, salting, drying, alcoholic fermentation, distilling, smoking, canning, and I’m probably missing something.

Our food regulation issues go beyond bartenders wearing gloves to mix Sazeracs. Food safety is good; I’m delighted to know that the flour I buy hasn’t been bulked up with talc. But as a culture, we need to reevaluate what defines “safe.” We need to find our cultural memories of foods that, as Katz says, inhabit that “creative space between fresh food and rotten food where most of human culture’s most prized delicacies and culinary achievements exist.” And the FDA and TTB need to catch up.

On Palate Press: Terroir is for Weirdos

My February piece for Palate Press takes a look at what wine lovers can learn about (I’d say, a more balanced, maybe more functional attitude toward) terroir. Does beer have terroir? Finding a definitive answer is, I think, less important and interesting than what we can learn by thinking through the question. It also gives me an excuse to mention Beers Made by Walking, an inventive and classically Oregonian project combining hiking, foraging, and beer. And Rogue Brewing Company, possibly the most creatively place-focused brewery in the country (at least among those big enough to sell beyond their own doors). These people embody so very much of what I love about being an Oregonian.

On Palate Press: Terroir is for Weirdos, and Other Place Lessons from Beer

Catching cheaters: detecting artificial carbonation in “authentic” beverages

Artificial carbonation is illegal for a variety of traditionally produced sparkling wines and French appellation d’origine contrôllée-designated and organic cidre. But how, once it’s in the bottle, is anyone going to tell whether a producer has cheated? Subjective sensory judgments are one thing, but a group of French chemists who’ve made detecting counterfeit tipples a specialty have devised a strategy for discriminating between legitimate and illigitimate bubbles. 

Carbonated beverages become carbonated in two ways. The first, “natural” way is to capture the carbon dioxide that yeast produce during fermentation by keeping the beverage under pressure while (at least part) of fermentation is happening. Traditional methode champenoise sparkling wines are carbonated this way: an already-fermented base wine is bottled under a crown cap (think beer bottle) with extra sugar, which yeast ferment to produce a bit more alcohol and carbon dioxide that, under pressure, dissolves into the wine to reappear as bubbles when release the pressure by opening the bottle. Traditionally made ciders and beers are also carbonated this way, as are home-made fermented sodas (not your Soda Stream), kombucha, and water kefir.

The second, “artificial” or “forced” way is to inject the beverage with carbon dioxide. Again, the gas dissolves into the liquid under pressure to be released upon enjoyment, but the source of the gas is a tank instead of a microbe*. Commercial sodas are carbonated this way, along with some cheap sparkling wines and the majority of mass-produced commercial beers (something against which the fine folks at the Campaign for Real Ale are fighting).

Unsurprisingly, natural carbonation takes longer and requires more skill and finesse to get right, is consequently more expensive, and is generally regarded as superior. Which means that some less-than-upstanding folk might want to pass off an injected drink as natural. Enter forensics.

Carbon-14 dating is used to determine the age, origin, and authenticity of fossils, bones, and other organic (once-living) artifacts (other types of isotopes are used to date rocks.) Carbon comes in multiple isotopes, or molecular versions numbered by how many neutrons they hold; 12C is the major version, 14C a naturally occurring minority. 14C is unstable and decays over time. While a plant or animal is alive, it constantly takes up fresh 14C from the environment; after it dies, the 14C in its body continues to decay without being replenished, which (I’m simplifying here) allows scientists to determine how long ago the thing died.

Carbon dioxide produced industrially (from petroleum) doesn’t contain any 14C; grapes and apples do, and therefore so does the carbon dioxide yeast produces from grape and apple sugars. So, we can determine whether a beverage has been artificially carbonated by looking at how much 14C it contains. If 14C levels are lower than the expected norm, someone’s cheating.

This concept isn’t new, but working out a practical method for analyzing samples and figuring out benchmark expectations for how much 14C shows up in natural versus injected beverages has taken some doing. The recent journal article describing that method looks at French AOC and organic cidres, but attests that testing sparkling wine (and beer and sparkling water) will work the same way. And while “carbon authentication” hasn’t yet been tested as evidence in a legal case, the authors conclude that, by their evidence, four of ten cidres bearing the organic label can be “strongly suspected” of illicit bubbling.

One more tool in the growing arsenal of anti-wine fraud tactics. As with the others, the real question is whether anyone will use it. Will this technique — plus Rudy Kurniawan et al. – herald an era of French governmental crackdown on sly producers? Or will everyone keep on happily humming along, knowing that the rules and “the rules” are a bit different? The industries’ (because there’s not just one wine industry, right?) approach toward authentic wines made using technically illegal methods, in the context of it’s attitude toward altogether counterfeit wines, stands to say something interesting about governmental and corporate priorities.

*Or, in the case of natural sparkling waters, a chemical reaction between acidic water and limestone.