Consumer Perceptions of Sulfites in Wine: How this Perception Influences Purchase Decisions

Sulfur dioxide has been used for many years as an antioxidant and antimicrobial agent in wine and most other food and beverage products.  Despite that only about 1% of the population has a true allergy to sulfites, there seems to be this relatively wide-spread perception that sulfites cause negative health effects in many more people.  Some consumers often report having headaches or migraines after drinking red wine, and while science has yet to prove a connection between sulfites and headaches, most consumers attribute their ailments to the sulfites present in wine.

This exaggerated misconception has led some wineries to produce what they refer to as “low-sulfite” wines, which are basically wines with little to no extra sulfites added.  Organic winemaking is known for producing these types of wine, as

Photo by George Cruikshank [Public domain], via Wikimedia Commons

Photo by George Cruikshank [Public domain], via Wikimedia Commons

added sulfites is not allowed in the production of organic wine.

The authors of the recently published article presented today wondered, if consumers are truly concerned over sulfites in wine, then how much would they value a low-sulfite wine, and how many of them would consider this quality important in their purchasing decision process?  To answer these questions, the researchers created surveys as well as performed “best-worst” experiments in order to determine consumer preferences and attitudes toward sulfites in wine; their willingness-to-pay for low or no-sulfite wines; and to identify a particular group of which low-sulfite wines could be successfully marketed.

METHODS

Participants were recruited via an email subscriber list at a wine and spirits retailer in northern Colorado.  As an incentive, participants were offered a $20 coupon for wine at the retailer for completing the study surveys.  Surveys were completed over a couple of weeks in March 2012, with a total of 223 participants completing the surveys.

The authors noted that the participants in this study do not represent the national average, as they tended to have higher incomes and higher education than the average American, but were typical of American college towns.

97% of the participants claimed to have purchased at least one bottle of wine during a typical month, while 32% of the participants claimed to have purchased between 4 and 6 bottles every month.

Surveys asked questions related to demographics, as well as alcohol purchasing habits.  Also, participants were asked if they have ever experienced a headache after drinking moderate amounts of certain types of wine.  If participants answered yes to this question, they were then presented with several questions aimed at determining what they thought caused these headaches.

After the headache questions, participants were given information regarding the role of sulfites in wine, as well as the current state of knowledge on the role of sulfites in human health issues.  The information stressed than only 1% of consumers actually have a true sulfite allergy, and that there is no scientific evidence to suggest that sulfites cause headaches in more individuals than that.

For the choice experiments, the researchers looked at 4 different quality levels, a “no-sulfites” wine label versus an “organic” wine label, and 4 different price levels.  Quality levels were determined by scores from the Wine Spectator.  Prices of wine were listed anywhere within $1.50 of three different “base prices”; $10.49, $20.49, or $30.49.  Each consumer was randomly assigned to either a Chardonnay or a Cabernet Sauvignon.

In other words, each participant experienced different price levels, quality, and no-sulfite/organic labeling, while the price

Photo by Flickr user thetejon

Photo by Flickr user thetejon

range and the type of wine varied across participants and not within a single participant.

Participants were given 12 choice tests with 3 wines each and were asked to select their “most preferred” and “least preferred” in each set.  Participants were allowed to select “would not purchase” if none of the options presented appealed to them.

After the preference selection, participants were then asked if they would actually purchase the wine they deemed as “most preferred”.

The random utility model and the rank ordered logit, logit and panel models were used in the analysis of results.

RESULTS

  • 34.08% of participants claimed to experience headaches after drinking a moderate amount of certain types of wine.
    • Headache claims decreased as education level increased.
    • Headache claims occurred more often in those purchasing fewer wines and less often than those purchasing more wines on a more regular basis.
  • When asked to select the three most important causes of headache after drinking certain wines, 63.16% of participants claiming headaches attributed the cause to sulfites, 57.89% to dehydration, 32.89% to red wine, and 20% to tannins.
  • Model calculations estimated the per bottle premium for non-sulfite wines in this experiment at $0.64, while the per bottle premium for organic wines was $1.22.
    • This result suggests that participants put more value on wines with an “organic” label than wines with a “no sulfite” label.
  •  A 4-point increase in the score of the wine resulted in $2.84 increase in willingness to pay.
    • This result, coupled with the previous result, indicates that participates put more value on wine scores than on the “organic” versus “no sulfite” label.
  • Participants reporting headache after drinking wine were willing to pay $1.23 for non-sulfite wines compared with $0.33 for those participants without headache experiences after drinking wine.
    • Those reporting headache were willing to pay more for wines with “no added sulfites” label than those with the “organic” label.
    • Even though organic wines do not contain added sulfites, the authors suggested that perhaps some of the participants weren’t aware of us, thus why “no added sulfites” wine was preferred to “organic” wine.
  • For all participants, the “organic” label increased likelihood of purchase by 1.86%, and the “no sulfites added” label by 1.72%, both of which were not significantly different compared with conventional labeling.
  • For all participants, a 4 point score increase increased the likelihood of purchase by 5.71%, and an increase in price by $1.50 decreased the likelihood of purchase by 5.10%, both of which were statistically significant.
  • Participants in the $20-25 per bottle group were 22% less likely than those in the $10-15 per bottle group to actually purchase their preferred wine in their group.
  • Participants in the $30-35 per bottle group were 33% less likely than those in the $10-15 per bottle group to actually purchase their preferred wine in their group.
    • Basically, as price per bottle increased, participants were less and less likely to actually purchase they bottle they claimed that they most preferred.
  • Participants experiencing headaches after drinking wine were 3.41% more likely to purchase an added sulfite-free wine, while those without the headache experience were not at all likely to purchase an added sulfite-free wine.

CONCLUSIONS

The results of this study indicated that 34% of the participants claimed to have headaches after moderately consuming certain types of wine.  After learning about what is known about sulfites, those participants claiming headache would still be willing to pay a $1.23 premium to purchase wines made without added sulfites.  Despite this increased premium, only 3.4% of those headache suffers would actually be more likely to purchase a wine made without added sulfites.  The most important factors for willingness-to-pay and likelihood of purchase in this study were price and wine quality, and not whether or not the wine contained sulfites or was labeled as organic.

Despite the fact that only about 1% of individuals suffer from a true sulfite allergy, these survey results showed that sulfites were commonly identified as the cause of headache from participants in this study.  The authors presented several hypotheses why this is the case, none of which were tested and would be great for future research studies.

Photo by Flickr user USDAgov

Photo by Flickr user USDAgov

In terms of marketing, the results of this study indicate that price and quality carry much greater importance for consumers in terms of willingness-to-pay and likelihood of purchase, and that putting a lot of time and resources into an anti-sulfites campaign may lead to negative consequences and fewer purchases.  If someone really wanted to market a “no added sulfites” wine, it seems as though individuals suffering from headaches after drinking certain wines may be the best bang for the buck, for as of right now, these consumers still seem to be somewhat poorly educated as to what exactly causes their “wine headaches”.  Even then, theoretically this campaign could only last for so long, as one would think eventually these consumers would become educated about sulfites in wine and would no longer be willing or likely to pay a premium on these bottles.

Though the sample was not representative of the average American population, the take-home message in this study appears to be that price and quality are much more important than “sulfite free” labels, and wineries should not only continue to try and produce quality wines at fair market prices, but also inform those less-educated individuals on the role of sulfites in wine and how this preconceived notion of sulfites in wine being bad for your health is misguided and inaccurate.

I’d love to hear what you all think of this study!  What other questions do these results raise for you?  Please feel free to share your thoughts/ideas/what have you!

Source: Costanigro, M., Appleby, C., and Menke, S.D. 2014. The wine headache: Consumer perceptions of sulfites and willingness to pay for non-sulfited wines. Food Quality and Preference 31: 81-89.

 

12 comments for “Consumer Perceptions of Sulfites in Wine: How this Perception Influences Purchase Decisions

  1. September 9, 2013 at 2:31 pm

    Becca, many of us in the indie know that there are many additives, preservatives and flavor enhancers in wine. When I designed and taught a class at the University of California-Irvine called, “Red, White and Green: Organic, BioD and Sustainable Wine, my research came up with a list of a couple of hundred. (I have the list if anyone is interested).

    In more expensive wines, there if often minimal intervention-from vine to grape to final product. I have always told my students, “drink less, but drink better!”

    • Becca
      September 10, 2013 at 12:30 pm

      Thanks for your great comments, Marlene! “Drink less, but drink better!” is a great saying! I love it!

    • September 10, 2013 at 1:33 pm

      I did an article titled Wine and Sulfites: Separating Fact from Fiction a few years back and based on the research I did, I came to the conclusion that more often than not, “wine headaches” were a result of over-consumption, not sulfites.

      I also found it interesting to learn that sulfites are present in so many of the foods we ingest, including fruit juices, dried fruit, pizza dough, cheeses, processed vegetables, baked goods, fried potatoes, and pickled foods. Imagine life without tater tots and capers!
      Bruce Nichols
      A Nichols Worth of Wine

      • Becca
        September 11, 2013 at 11:01 am

        Thank you for your comments, Bruce, and thank you for mentioning your article!

        No way in hell I can imagine a world without tater tots…..NO! ;)

  2. September 10, 2013 at 10:51 am

    Excellent and intersting piece, and valuable comment.

    • Becca
      September 10, 2013 at 12:31 pm

      Thanks for reading, Betsy!

  3. September 10, 2013 at 11:49 am

    Everyone is quick to blame sulfites for headaches when the more obvious cause is histamines which are present in red wine but not white. Sulfites are present in both red and white wines and many people only get headaches from red wine.

    • Becca
      September 10, 2013 at 12:31 pm

      Totally agree! It’s just so odd to me that the misconception still continues!

  4. September 11, 2013 at 12:12 am

    I also read that more people have an allergy to alcohol than to sulfites? No sure if this is true. Regardless I fell that using less sulfites is not a bad thing.

    • Becca
      September 11, 2013 at 11:02 am

      Thanks for your comments, Nicolas. Certainly, I bet that’s true for some folks! I’d be willing to bet it isn’t just one thing—it could be the histamine, the sulfites for the minuscule number of folks, the alcohol, etc etc. Good thinking!

  5. Ignacio Rodriguez
    February 6, 2014 at 3:59 am

    “Basically, as price per bottle increased, participants were less and less likely to actually purchase they bottle they claimed that they most preferred.”
    Over and over I read this statement and am awed by its incoherence. Why don’t people who spend more money on a bottle of wine buy what they want? Do we doubt our choice the more expensive the bottle gets and depend on other criteria?

    • Becca
      February 6, 2014 at 12:29 pm

      That’s a good question, Ignacio! Maybe it depends upon their own personal financial situation? Perhaps at a certain point the amount of pleasure they receive drinking their more preferred bottle doesn’t outweigh the increased cost? Purchase behavior really is a tricky thing :)

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