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WINEMAKING of an immune response caused by the amplification of an antigen (usually a protein) binding to an antibody that specifically recog- nizes it, stimulating a mast cell or T-cell to emit chemical irritants such as histamines that orchestrate a physiological response. However, other sensitivities to sulfites dissolved in foods have been shown to occur, although quite rarely (estimated at two sen- sitive individuals per 1 million Americans.9 ) The principal cause is a genetic deficiency of the enzyme sulfate dehydrogenase in the liver, which can lead to severe reactions to high-sulfite foods such as fish and dried fruits. The principal hazard from sulfites, both to consumers and workers, is the inhalation of SO2 gas, an element of smog that is volatilized when food is acidified. The practice of sprinkling pure sodium bisulfite on lettuce was banned by the FDA in 1986 because it led to confirmed deaths from respiratory failure when the lettuce was acidified with vinegar dressings, liberating high concentrations of the gas to be inhaled by luckless diners. This was not an allergy but simply the inhalation of an acidic gas that shifts blood pH below the range in which it can transport oxy- gen, causing death by asphyxiation, exactly as sometimes occurs in wineries when workers inhale CO2 . Repeated or prolonged exposure to atmospheric irritants can wines is that the amount in question is a few parts per million rather than an acidification of the pure chemical. The worst we experience is a slight tickle of the nose in a low-pH wine (this cause increased sensitivity to sulfur dioxide, particularly in asth- matics who have respiratory immune response to allergens such as mites, cat dander and other proteins. The FDA estimates that 1% of Americans are hypersensitive to inhaled sulfur dioxide.10 The reason severe reactions to inhaled SO2 do not occur in is very common in German wines below pH 3.0), which may make us sneeze. These wines are usually not very high in FSO2, but they appear so because a high proportion is in the volatile molecular form. Despite three decades of disinformation from neo-Prohibition- ists, no confirmed ill health effect of any kind has ever been at- tributed to sulfites in wine, and sulfites remain on the FDA's GRAS list, generally regarded as safe. Bowing to political pressure, BATF agreed in 1986 to require sulfite labeling on U.S. wines in a ruling articulating a long list of sensible objections.11 Digital Edition Now Available To Subscribers New rules The most important omission in my 1980 article was to point out the folly of applying the table to high-pH wines. If your wine is pH 4.0, you want to correct the pH, not try to stabilize its micro- biology by maintaining 120 ppm FSO2. This applies to winemak- ing above 3.6, the peak of the bitartrate curve, which constitutes a natural watershed dividing winemaking into low- and high-pH regions. High-pH winemaking concerns itself mostly with red wines, which have more vigorous anti-oxidative phenolic reac- tions in this zone and greater maturation requirements. The dominant theme of low-pH winemaking is focused on prevention and control. In high-pH winemaking, we often ac- Wines with low pH can cause a tickle in the nose or prompt a sneeze. Read it, Search it, Share it, Download it! Call or visit our subscribe page to opt-in today. (866) 453-9701 • winesandvines.com strategic capital and expertise for the wine industry www.bacchuswinefund.com (415) 828-8898 bacchuscapital@bacchuswinefund.com 60 Wines & Vines MARCH 2012