Sulfur dioxide has been used for many years as an antioxidant and antimicrobial agent in wine and most other food and beverage products.Â 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.Â 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 â€ślow-sulfiteâ€ť wines, which are basically wines with little to no extra sulfites added.Â Organic winemaking is known for producing these types of wine, asadded 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?Â To answer these questions, the researchers created surveys as well as performed â€śbest-worstâ€ť 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.
Participants were recruited via an email subscriber list at a wine and spirits retailer in northern Colorado.Â As an incentive, participants were offered a $20 coupon for wine at the retailer for completing the study surveys.Â 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.Â Also, participants were asked if they have ever experienced a headache after drinking moderate amounts of certain types of wine.Â 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.Â 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 â€śno-sulfitesâ€ť wine label versus an â€śorganicâ€ť wine label, and 4 different price levels.Â Quality levels were determined by scores from the Wine Spectator.Â Prices of wine were listed anywhere within $1.50 of three different â€śbase pricesâ€ť; $10.49, $20.49, or $30.49.Â 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
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 â€śmost preferredâ€ť and â€śleast preferredâ€ť in each set.Â Participants were allowed to select â€śwould not purchaseâ€ť 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 â€śmost preferredâ€ť.
The random utility model and the rank ordered logit, logit and panel models were used in the analysis of 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 â€śorganicâ€ť label than wines with a â€śno sulfiteâ€ť label.
- Â 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 â€śorganicâ€ť versus â€śno sulfiteâ€ť 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 â€śno added sulfitesâ€ť label than those with the â€śorganicâ€ť label.
- Even though organic wines do not contain added sulfites, the authors suggested that perhaps some of the participants werenâ€™t aware of us, thus why â€śno added sulfitesâ€ť wine was preferred to â€śorganicâ€ť wine.
- For all participants, the â€śorganicâ€ť label increased likelihood of purchase by 1.86%, and the â€śno sulfites addedâ€ť 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.
The results of this study indicated that 34% of the participants claimed to have headaches after moderately consuming certain types of wine.Â 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.Â Despite this increased premium, only 3.4% of those headache suffers would actually be more likely to purchase a wine made without added sulfites.Â 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.Â The authors presented several hypotheses why this is the case, none of which were tested and would be great for future research studies.
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.Â If someone really wanted to market a â€śno added sulfitesâ€ť 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 â€świne headachesâ€ť.Â 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 â€śsulfite freeâ€ť 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.
Iâ€™d love to hear what you all think of this study!Â What other questions do these results raise for you?Â Please feel free to share your thoughts/ideas/what have you!