Will magnetic yeast make better Champagne?

UPDATE: Deborah Parker Wong has written a detailed discussion of magnetic yeast technology and its implications for the Champagne and sparkling wine industries for the September-October 2014 edition of Vineyard and Winery Management in which she makes it clear that I’m wrong about #3 below: at least some traditional producers are enthusiastic about rapidly making use of the new technology. The full text of Wong’s article is available for free via her website.

Wine Searcher ran a story this past week about new technology from the University of Ljubljana that speeds traditional sparkling wine processing times by magnetizing yeast cells. Magnetic nanoparticles affixed to the cells’ surface don’t interfere with fermentation and let winemakers literally and near-instantaeously pull the yeast into the neck of the bottle by applying a magnetic current. Since riddling — slowly inverting and rotating bottles to remove (unattractively cloudy) dead yeast after the secondary in-bottle fermentation responsible for effervescence-generation — traditionally takes a few months and a LOT of hands-on work, a 15-minute flip-a-switch solution looks pretty attractive. BUT:

Interesting fact #1 – This technology isn’t new, though applying it to the sparkling wine industry is. Bioengineers came up with magnetic yeast in 2009.

Interesting fact #2 – If actually adopted by the industry, magnetic yeast will be far from the only use of nanoparticles in food. Quite the contrary, which you know if you follow the American health and science news. Titanium dioxide nanoparticles are common additives to everything from chewing gum and toothpaste to yogurt and soy milk, generally to the effect of making whateveritis whiter. Nanosilver particles are common both as agricultural pesticides and in antimicrobial coatings for household goods, and nanolipids and nanoproteins and assorted other nanostuff finds its way into all manner of food-related items. The consensus is that we don’t yet have a consensus on whether and to what degree ingesting nanoengineering is safe (a peer-reviewed take on that question here; a more accessible and more inflammatory story from Mother Earth News here). Logically, magnetic force should effectively pull all of the magnetic particles (made from magnetite, if the Ljubljana authors are using the same general strategy published in the 2009 paper) out of the wine, but nothing is perfect. If residual particles remain, drinking them might be a health risk, but it won’t be a unique one.

Interesting fact #3 – Alright; this one isn’t a fact. It’s a speculation based on fact. I speculate that we needn’t worry too much about magnetite in our celebratory libations. Champagne in particular and high-quality, methode champenoise sparkling wine in general, is not about fast. Exactly the contrary. Champagne legally has to spend at least 15 months in bottle and at least 12 months on the lees, and usually exceeds that by a year or two because age on the lees is vital to the flavor profile of high-quality sparkling. I reviewed some of those considerations in this article for Palate Press.

The problem with riddling isn’t the time per se so much as the labor: some poor guy has to spend his days jiggling bottles (and if champagne riddlers don’t have a high incidence of occupation-induced carpal tunnel syndrome, I suspect that it’s just going undiagnosed). The gyropalette solves that problem by loading a box full of bottles onto a modified forklift and letting the machine jiggle them for you. That bit of technology has been popular and successful, but it seems to me that it’s also a lot less expensive than magnetic yeast.

Think about it. Yeast reproduce in the bottle, a lot. So, every yeast cell used in inoculation needs to be loaded with magnetite particles to ensure that all of its many, many offspring has at least one magnetite particle.** Don’t even think about generating your own yeast innoculum. And that’s before we get to the magnetic set-up to actually pull down the yeast. I don’t know. Storing wine (and paying that poor guy) is expensive. Maybe this is a cost-effective solution. But if high-end producers aren’t going to be seduced by speed, and if lower-end producers are disinclined to spend more money on production technology, and if the wine industry in general tends to be stuck in the mud, I suspect we needn’t worry too much about drinking magnetite anytime soon.

** Maybe effective clarification doesn’t require that every yeast cell be magnetic, if the yeast tend to stick together (flocculate) and magnetic cells will help pull down their non-magnetic neighbors. Without reading the paper I don’t know, and since I can find neither the paper (maybe it’s not yet been published, or maybe it wasn’t published in English) nor the specific names of the researchers nor any other mention of the research on the University of Ljubljana’s website I have to speculate. It’s disturbing that I can’t find another source backing up the Wine-Searcher article (and I don’t personally know it’s author and can’t locate him via the usual tricks) but, then again, I don’t read Slovenian.

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.