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WINEMAKING flavor impact (a soapy finish can be detect- ed at about 200 ppm) and because of its inhibitory effect on malolactic bacteria at about 100 ppm. For those seeking a more detailed ac- count of SO2 chemistry and use, an ex- the rate of sulfite-to-sulfate oxidation in low-pH wines is insignificant. In high- pH reds, however, the production of the strong sulfuric acid can significantly low- er pH while increasing TA only slightly. Even at high pH, this takes years for a change worth noting, but for many years it was the only legal way to add acid in many French AOCs (thus their election to express TA as sulfuric rather than tartaric acid.) The resulting sulfate has an appe- tizing bitterness that is characteristic of Bordeaux and Chianti. Total SO2 should be measured to assess ble's sensory science graduate class at UC Davis in 1982 remains the only credible determination of sulfite aroma thresholds yet conducted—apart from Harold Berg's laughable 1955 work,7 which established pH 3.3 as 120 ppm FSO2, which any nov- ice will tell you is way off base. the free SO2 threshold for a white wine at tremely thorough discussion by Ben Rotter is available online.6 How much is too much? There can be no greater indictment of the pick-and-shovel enology research yet to be done than the unlikely circumstance that, as far as I am aware, the SO2 threshold study Pat Howe and I conducted as stu- dents in Rosemarie Pangborn and Ann No- Enology really is a scientific side street, and opportunities to enhance our grasp of the most basic matters reside at every turn. and I worked out a simple way to do this. Apart from this homespun method, the latest embodiment of the Foss WineScan system is the first analytical instrument to perform a direct headspace reading of mo- lecular SO2 There is much to be said for directly measuring headspace molecular SO2 . Pat in the gas phase. This requires that the sample is neither acidified nor heated, a departure from the standard pro- tocol. A shock awaits the industry when they learn what they really have. A word of encouragement to novices: Pat and I never set out to do anything other than survive the exacting scrutiny of Dr. Noble, never dreaming the results of the work and the innovation of quad- rangle screening would have any larger consequence. Enology really is a scientific side street, and opportunities to enhance our grasp of the most basic matters reside at every turn. Wine and health Not much new information has surfaced since 1984, when I published a synopsis of considerations surrounding wine and health.8 The Wine Institute funded exten- sive Ames testing in the 1960s, conclud- ing that sulfur dioxide as used in wine is not a carcinogen, a finding that has never been challenged. Because of its small size (MW=64 daltons), it is unlikely that SO2 can act as an allergen, and since the hu- man body produces one gram per day of sulfites, the belief held by many Americans that they are allergic to sulfites is probably groundless in the technical medical sense Get the best out of your grapes. The Europress exclusively by Euro-Machines Euro-Machines offers high-quality equipment based on your vision to bring out the best of every vine, with our proven history in the careful handling of grapes and together our love of good wine. Europress 6-320 hl Europress-Cool with cooling jacket Euroselect berry selector Destemmer crushers Sorting equipment Conveyor belts Vibrating tables Custom-made tanks Pumps Braud grape harvesters and much more Euro-Machines, Inc. West: Fairfield, CA 94534 - Phone 707-864-5800 East: Culpeper, VA 22701 - Phone 540-825-5700 info@euromachinesusa.com www.euromachinesusa.com A subsidiary of Scharfenberger Company Germany Wines & Vines MARCH 2012 59