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WINEMAKING nothing in the Davis research deals with the problem of colloidal disruption. Colloids are a slightly weird form of matter, with a status somewhere between those substances that are in solution in a liquid—like sugar and alcohol in wine—and those that are merely suspended, capable of being taken out either by gravity or filtration—like dead yeast and fruit flies. All manner of things can, separately or together, take on colloi- dal form (tannins, anthocyanins, proteins, polysaccharides, etc.) and be distributed throughout the volume of liquid. At high enough levels, colloids can clog filters. In more normal amounts, acting as a kind of matrix or maybe a force field, the entirety of the colloidal material can be more signifi- cant than its many component parts. If this is starting to sound a little woo-woo, re- member that without colloids, we wouldn't have milk or ink as we know them. So, Smith suggests, if you ram all this nice colloidal material through a sterile filter, you will bust it up. The individual molecules may get through the filter (and get measured by David Block's students on the other side), but the matrix can get damaged beyond repair. That disruption can have implications for the perception of tannins and mouthfeel, for the retention of aromatics, for how a wine deals with oxi- dation and for longevity. As a daily user of both milk and ink— not to mention wine—I would love to know more about this netherworld be- tween solution and suspension, and so would a lot of people. Maybe the colloidal level holds the secret to the mouthfeel of that fat Chardonnay Luke Bohanan wishes somebody would test with rigorous filtra- In light of the work at Davis, it seems to me that the ball is now in the colloidal court. tion methods. Roger Pachelbel of Gusmer, a former production winemaker who kept in touch with the Davis project, wonders if the phenomenon of bottle shock is a reflec- tion of colloidal material getting knocked around—by bottling as well as filtration— and then putting itself back together in the bottle over time. The other point about colloids in wine R&D_Jan08 11/12/07 3:54 PM Page 1 on which everyone agrees is that they are not well understood, which threatens to Glass Apparatus for the Wine Laboratory Acclaimed by enologists across the continent! The RD80 Volatile Acid Still is an improvement on the Cash Still for determination of volatile acids in wine. It features an aspirator pump to remove the spent sample, which speeds testing, saves water, avoids repair bills, and prevents cross contamination of samples. get us back to an earlier stage of the filtra- tion debate: Opponents saying filtration takes out the special sauce, and propo- nents asking, "What special sauce?" In light of the work at Davis, it seems to me that the ball is now in the colloi- dal court. We would need to know much more about how wine colloids form and un-form, how winemakers could proceed to encourage more (or less) of them and how we could easily measure the type and extent of colloids in a particular wine. For the moment, there is no convenient hand- held colloidometer on the market that is suitable for measuring the colloidal index of a wine, especially since no one has de- vised a colloidal index to measure. And back to the sensory part: It's true that there's a difference between not find- ing a difference and proving there is no dif- ference. But if no one can detect it, how much does it matter? Tim Patterson is the author of "Home Skolnik_Dir10_Jan10.qxd 10/19/09 10:04 AM Page 1 Winemaking for Dummies." He writes about wine and makes his own in Berkeley, Calif. Years of experience as a journalist, combined with a contrarian streak, make him interested in getting to the bottom of wine stories, cast- ing a critical eye on conventional wisdom in the process. The R&D SO2 Apparatus uses the Aeration- Oxidation Method to maximize testing accuracy. It is specifically designed for this test in con- sultation with enologists. Flexible spherical joints and interchangeable flasks facilitate simple operation and minimize breakage. We manufacture a full line of wine laboratory equipment, and also provide Glassware Design Engineering, Custom Fabrication, and Repair Services. CALL, FAX OR WRITE FOR OUR CATALOG OF WINE APPARATUS. Research & Development Glass Products & Equipment, Inc. 1808 Harmon Street • Berkeley, CA • 510-547-6464 • Fax 510-547-3620 E-mail: RD1967@aol.com • Web site: http://go.to/RandD Suppliers of Lab Glassware to the Wine Industry since 1967 SKOLNIK INDUSTRIES, INC. 4900 SOUTH KILBOURN AVENUE CHICAGO IL 60632-4593 PHONE 773.735.0700 FAX 773.735.7257 TOLL FREE 1.800.441.8780 HTTP://WINEDRUM.SKOLNIK.COM EMAIL: SALES@SKOLNIK.COM WINES & VINES NOVEMBER 2012 95 STAINLESS STEEL COOPERAGE Providing leading wine makers with stainless steel barrels of high quality, durability, and design.