How to Make Food Sweeter Without Adding Any Sugar

Research explains how round shapes make foods taste sweet.

Posted Apr 05, 2018

Do you want to make a lightly sweetened dessert taste sweeter without adding any sugar?  Serve it on a round plate. 

Research has shown that seeing round shapes makes us perceive sweetness more intensely.  Even being primed by a round shape works.  Participants who were shown black and white line drawings of rounded shapes such as circles and ellipses prior to rating the sweetness of water were able to detect sweetness in barely sugared water, while those who had been shown angular shapes like triangles or squares could not.  In another experiment, participants who were served cheesecake on round white plates perceived the cheesecake as 20% sweeter than participants who ate the cheesecake from square white plates. Even savory dishes become sweeter when the plate they are served on is round.  Merle Fairhurst and her colleagues at the Centre for the Study of the Senses at the University of London found that a vegetable appetizer  served on a round plate was perceived as 17 percent sweeter than when the same appetizer was served on a square plate. 

Indeed the extra sweetening effect of roundness can be so potent that it backfires.  In a newsworthy example of such a fiasco, The Telegraph reported on a revolt among loyal Cadbury Dairy Milk bar consumers in Britain in the fall of 2013 when a new shape of the iconic chocolate bar was introduced.  According to the newspaper, angry Dairy Milk fans thought the chocolate now tasted “too sugary” and “sickly.” However, Kraft, which bought Cadbury in 2010, insisted that the recipe was unchanged.  If Kraft was being truthful, why were so many candy bar eaters unpleasantly surprised? The answer is that the new shape of the chocolate pieces was now rounded, while the original chocolate pieces had been squares.

We automatically connect sweet tastes to round shapes because of the sensory correspondences we have learned through our experiences with the world around us. Fruits, which are inherently sweet, are either roundish or curved.  Round is also the shape of many familiar desserts, such as ice cream scoops, cookies, and cupcakes. But the connection between shape and taste is not innate.  In a recent investigation on shape and taste matching with the Himba of Kaokoland in Namibia, an indigenous hunter-gatherer people who have no written language and no access to modern markets and advertising, it was found that they matched bitter taste with rounded shapes.  This means that in order for sweetness to be intensified by round shapes you have to have regularly experienced roundness in the context of sweetness— as we do in cakes, pies and donuts—to name just a few.

Luckily, since we have been exposed to copious iterations of rounded desserts we can benefit from the perceptual synergy that occurs between our senses when our eyes see round shapes and our mind makes our tongues sing with more sweetness.  So go and enjoy dessert with no added sugar more now by serving it on a round plate.

References

Herz, R. (2017). Why You Eat What You Eat: The Science Behind Our Relationship With Food. New York: W.W. Norton and Company.

http://www.dailymail.co.uk/news/article-2421568/Revolt-Cadburys-rounder-sweeter-bars-Not-classic-rectangle-shape-Dairy-Milk-changed-customers-also-sugary.html

Fairhurst, M. T., Pritchard, D., Ospina, D., & Deroy, O. (2015). Bouba-Kiki in the plate: combining crossmodal correspondences to change flavour experience. Flavour, 4, 22. DOI: 10.1186/s13411-015-0032-2

Liang, P, Roy, S., Chen, M-L. & Zhang, G-H (2013). Visual influence of shapes and semantic familiarity on human sweet sensitivity. Behavioral Brain Research, 253, 42-47.

Spence, C. (2014). Assessing the influence of shape and sound symbolism on the consumer’s response to chocolate. New Food, 17, 59-62.

Stewart, P. C., & Goss, E. (2013). Plate shape and colour interact to influence taste and quality judgments. Flavour, 2, 27. DOI: 10.1186/2044-7248-2-27.