Sulfites & Wine

May 10, 2017

By Frank Dominic Puzio

To a consumer, the word sulfite in regard to wine generally has a negative connotation.  We have become accustomed to warning labels on many consumable products, and for wine, it is a government mandate to alert the consumer that the wine product contains what many believe as those dreaded sulfites.  Falsely or otherwise, sulfites are blamed by many for wine headaches and varied ill-effects experienced subsequent to wine consumption.  It is often expressed from people traveling to countries like Italy and France…

“My wife and I were in Europe and we had much more wine than we typically consume in the States and we never experienced a headache or undesirable after-effects.  I’m sure it’s because they don’t put sulfites in their wine like they do here.”

I have personally had the opportunity to discuss this topic with numerous European winemakers about this claim, and they all reveal, “but of course we use sulfites in our wines.  The wines must be protected.”   So what’s the truth?  The European winemakers do admit that their wines sold in their local European markets generally have less sulfites than their exported products to the US.  In truth, it would be extremely rare to find a wine produced and bottled without sulfites.  Only very recently there is there a trend to use less.  As an aside, ascorbic acid (Vitamin C) can be used to protect wine, but it is not a likely to keep the wine fresh for long periods of time.  And yes, even organic wines contain some amount of protective sulfites.

You should be aware that sulfites are a naturally occurring compound that nature uses to prevent microbial growth.  They are found on grapes, onions, garlic, and on a host of other growing plants.  So in reality, no wine can ever be “sulfite free,” because of this natural occurrence within the grape itself.  Dried fruits such as apricots have 10-15x more sulfite content than that contained in the government regulated amounts allowed in red wine.  Most often the labeling on dried fruits has no warning printed that they contain sulfites.  If one does suspect sulfite sensitivities some suggest that an easy way to see if they are a problem for you is to eat a food high in sulfites, say dried apricots, and if a reaction is experienced you can generally confirm a negative reaction to sulfites in this manner.  In my research for this topic, it was stated that people truly allergic to sulfites may also be asthmatic or people with varied levels of respiratory concerns.

In regard to modern winemaking , the natural amount of sulfite contained in the grape is not at all sufficient to protect the wine during the winemaking process or to insure the long-term quality of the product for commercial consumption.  The crushed grape must be protected to discourage or suppress unwanted wild natural yeasts in the fruit and also to protect it from harmful bacteria and mold spores.  At specific subsequent stages in the wine making process carefully calculated amounts of sulfite are added for the same reasons.  Anytime wine is exposed the oxygen subsequent to the initial process of fermentation, the risk of flavor and color damaging effects escalate due to harmful oxidation.  In summary, the addition of sulfites during winemaking stages is a delicate balance to control spoilage and unavoidable exposure to oxygen.  Even during barrel aging, and to a lesser extent in a corked bottle, oxidation from oxygen is ongoing.  Just the right amount of free-sulfite ions help insure a fresh and enjoyable product.

The sulfite chemical most winemakers use to protect their wines is, K++Meta Bi-sulfite, abbreviated (SO2).  Interestingly, sulfites have been used since ancient times for many purposes, including the cleansing of wine receptacles by the Romans, Greeks and Egyptians.  As a food additive they have been used since the 17th century and approved for use in the United States as long ago as the early 1800’s.

The antioxidant and anti-microbial properties of SO2 that has gained it an imperative role in winemaking by again preventing the unwanted organisms that would turn wine into vinegar in a matter of months, but also there is secondary benefit that allows the wine to better develop its potential in regard to complex flavors we all find enjoyable in fine wine.  Using an example we all have experienced, if you take a bite out of an apple, and leave it sit for a time, we would notice a browning discoloration to the fruit rather quickly, and in addition, if we took a subsequent bite into the same area of the apple it would not be as flavorful.  Sulfites will protect our grapes from this same fate and help guarantee a long-lasting flavorful product.

I am pleased to report that a small production winery such as our First Crush Winery has an advantage to control the levels of sulfites introduced during all of the winemaking stages.  First Crush wines contain approximately 40% less sulfite additions than typical commercial wines.

There are terms called “total SO2” and “free SO2.”  Total SO2 is defined as the total amount per volume added from the beginning crush to bottling, and free SO2 is the amount remaining in the wine at any given time after the chemistry of the whole process dissipates some of the total.   Obviously the only meaningful variable for the consumer is the amount of free SO2 in the wine at bottling.

Going back to the topic of allergies and headaches from wine consumption, sulfite allergies are a problem for a few wine drinkers, just like some people are allergic to peanuts.  FDA studies note that as many as 1 in every 100 people may have some sort of sulfite sensitivity.  I often hear, “Red wine gives me a headache, so I can only drink white wines.”  Those folks may find it surprising that white wines generally have higher levels of sulfites than red wines.  The literature indicates that when complaints of headaches are experienced after red wine consumption it is now thought that this is not technically an allergic reaction but rather what is being described as “the red wine headache syndrome.”  In most cases, these headaches are not thought to be related to the sulfite content in the wine but rather due to other natural substances contained within red wine such as histamines, tyramine, and phenolic flavonoids found in the skins of the red grape.  Since red wines are fermented on the skins, more of these compounds remain in the final red wine product.  Aside from the discomfort of the headache, these symptoms do not appear to be a risk for progression to a more serious reaction.

Is there a remedy?  Some studies have suggested that these headaches can be avoided, or minimized, by taking aspirin or ibuprofen prior to drinking wine.  As an aside, do not take acetaminophen (Tylenol) while drinking alcohol since it is toxic to the liver.  It must be understood that true adverse reactions to sulfite occur quickly, within the first 30 minutes, and headaches and ill-effects long after the fact, or the next day, are to be considered symptoms of excess consumption involving dehydration.  Enough said. I’m getting a headache!


Dr. Frank Puzio