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WINEMAKING same mechanism to stop crystal formation: macromolecules of the selected mannoproteins hamper the growth of certain crystal faces, altering the shape of the crystals and keeping them from becoming precipitation-worthy. The material being added by these products is ultimately yeast, a substance that has been in every wine since before it was wine, so the addition can be construed as quite natural (and indeed as organically certified.) You might think of it as lees aging, only in a bag or a jar, precisely measured. Carboxymethyl cellulose (CMC) provides an alternative monkey wrench to throw into the crystal formation machinery. Two CMC products, using cellulose derived from wood, are currently in limited, trial distribution in the U.S.: Enartis Vinquiry's Cellogum and Laffort's Celstab. CMC inhibits microcrystal nucleation and growth; it's not quite the same chemistry as what mannoproteins do, but the results are similar. CMC products are not recommended for red wines, since their interaction with pigment can have unpleasant consequences. Finally, all the major fermentation product suppliers offer stabilizing agents based on gum arabic, an extract of acacia tree sap. While the main selling point of these products is their contribution to mouthfeel structure, masking tannins or preventing pigment precipitation, many of them also contribute to the crusade against unwanted bitartrate crystal formation. Prognosticating precipitation Before we get to the fine print, one more advantage of the new waves of technologically driven alternatives to traditional cold stabilization: They all work much faster. The membrane filtration methods can process in a day the volume of wine that would need ScottLabs_May08 4/2/08 9:53 PM Page 1 two weeks or more in tank; the mannoprotein and CMC additives can often just be tucked into the final steps of filtration and bot- tling. Faster processing also comes into play from an entirely dif- ferent angle, particularly for red wines. Under economic pressure, many wineries have moved red production from barrels to tanks with oak chips or simply shortened times for barrel aging; as a result, the natural processes of lees contact and gradual tartrate precipitation don't have time to play out, leading to an increased need for red wine stabilization. Alternatives to traditional cold stabilization require careful analysis to estimate the degree of potential instability. All these technologies and products originally were developed in Europe, where all of them are approved by the relevant regulatory bodies for everyday use. The picture in the U.S. is more complicated, with things in various stages of scrutiny and approval by the FDA or the TTB. WineSecrets' STARS electrodialysis is fully approved; Mavrik offers its stabilization services in the U.S., but VA Filtration currently only performs this work in Chile and Australia, pending clarification of certain issues with the TTB. The mannoprotein products have TTB approval, while the CMC products are in an earlier experimental stage. In five years, all of this will be readily available; for the moment, check with your supplier. 50 Wines & Vines APRiL 2012