There is no sincerer love than the love of food.

Posted by Crispin Boon on the 17th February, 2020
Our perception of Taste in the role of product development and sensory testing is much more complex than it at first appears. Our associated product perception(s) go way beyond just the quality of the ingredients in the food that we place in our mouth.

When faced with the challenge of creating a ‘great tasting’ recipe or dish – many people would start with examining the quality of the raw ingredients. And on the face of it – this is a logical place to start. However, at Walnut Unlimited our knowledge of human understanding means we also know that our perception of Taste goes way beyond just what we put in our mouth. Instead, our senses are in a continual state of overdrive – whether we are aware of them or not.

In truth, our perception of Taste is just one part (albeit a critical one) of the overall food quality equation that also includes Sight, Sound, Smell and Touch. As celebrity chef Heston Blumenthal so eloquently put it: “We eat with our eyes, ears, nose, memory, imagination and our gut.” (2)

Indeed, at Walnut Unlimited our own research has demonstrated time-and-again that product perception can be fundamentally affected by more than just the quality of the raw ingredients. Instead the latest developments in neuroscience have confirmed that our perception of Taste is multimodal. The more senses that are activated by interacting with a product – the sight, the sound, the smell, the touch – the more memorable the food (and brand) experience.


Whilst we may not like to admit it (or be blissfully unaware) – our perception of Taste is affected by visual cues such as the shape and colour of the food we eat. For example, when Cadbury’s changed the shape of their Dairy Milk bar in 2013 from the traditional rectangular block to utilising a more curved segment there was a public outcry. The Daily Mail newspaper reported how consumers were convinced the formulation of the chocolate bar had also changed, complaining of a sweeter, more sugary taste. (3) But this was not the case.

The extent of the indignation forced Mondelez International to make an official statement that: “We have been very clear and consistent that we have not changed the recipe of the much-loved Cadbury Dairy Milk, although it’s certainly true that we changed the chunk last year from the old, angular shape to one that’s curved.” So how do we square this circle?

The answer may lie in the work of Gallace, Boschin and Spence (4) who demonstrated that in the context of chocolate, consumers will typically match the sweeter taste of milk chocolate with rounder shapes whilst pairing the more bitter taste of dark chocolate with angular shapes.

In another example, the Taste perception of a café latte beverage has been shown to be influenced by the colour of the mug from which it was drunk. A white mug enhanced the rated bitter ‘intensity’ of the coffee flavour; by contrast the same coffee drunk from a blue mug was perceived as sweeter and more acceptable. (5)

The understanding that how our food is presented can sub-consciously affect our taste perception has big implications for many of our favourite grocery products. Take for example, a scenario where a brand may be actively looking to reformulate a product to help with sugar reduction. The work of Charles Spence et al suggests that some of the negativity associated with reduced sweetness could potentially be offset (to a degree) by changing the shape and colour of that product or packaging.

However, any change associated with that product reformulation also needs to be approached and handled with sensitivity. Depending on the product type, there still needs to be a natural congruency between the colour of the food and the type of product being tested. If a food or beverage is perceived to be a ‘wrong colour’ then consumers can adversely react to that visual stimulus versus a ‘proper coloured’ version of the same product. (6)

At Walnut Unlimited, with our unique blend of product, sensory and neuroscience expertise, we have ways of measuring and capturing these subtle but important differences in how products are perceived – whether people can articulate them or not.


Over-and-above Sight, the simple process of eating food or drinking a beverage can create Sounds which over time become associated with (and influence) our sense of Taste and flavour. In evolutionary terms, the use of Sound would have had an important role to play in terms of signifying a crisp ripe apple (for example) as opposed to warning of a softer (potentially rotting) fruit. Today, there is evidence to support the idea that altering the Sound of our food can also affect overall perception without any corresponding physical change in the product texture. For example, in a study using potato chips, Spence & Zampini (7) found that the perception of ‘crispness’ and ‘staleness’ were altered by varying the loudness or pitch of the crunching noise. When the sound of crunching was amplified, participants rated the potato chips as both crispier and fresher tasting.

Similarly, experiments have demonstrated that when a soft drink can is opened, its pitch and tone can be manipulated to make the contents seem fizzier and fresher. By contrast, the lack of any fizz, when it is expected, can often be interpreted that the contents are old or stale. And we can all recall the satisfying ‘pop’ of a cork being extracted from a bottle of wine which can add to a sense of occasion and help raise our sensory anticipation – a phenomenon which was measured as part of The Grand Cork Experiment in London (2017). (8)

Sound clearly also has a critical role to play in helping drive our overall perception of Taste.


Our sense of Smell can often be overlooked in the quest for Taste. However, the reality is that the two are intrinsically linked. As humans, we ‘smell’ our food via two routes – directly through the nostrils and up through the back of the throat – and it is often hard to separate the two. So, when we talk about Taste we are often really talking about an amalgamation of both Taste and Smell: “Smell and taste are in fact but a single composite sense, whose laboratory is the mouth and it chimney the nose…” (9)

We now understand that once a smell is experienced alongside a specific flavour, the two can become associated – especially with repeat exposure. So, through our life-experiences, our sense of Smell can influence our perception of Taste – and vice-versa. As a result, we may often find ourselves describing a product as ‘sweet’ e.g. when smelling a stick of candy floss – but sweetness is really a Taste that we have grown-up to associate with the smell of sugary food. (10)

Armed with this knowledge, it is easy to understand that the strong aroma ‘rush’ you receive when you first open a jar of coffee is not there by accident. Instead it has been cleverly designed and carefully engineered into the jar opening process to provide a sensory experience specifically designed to signify freshness and quality by the manufacturer.


Finally, our perception of Taste is not just about Sight, Sound and Smell. Instead, haptic information from our hands can affect our perception of texture – and the tactile ‘feel’ of an item in our hands can fundamentally affect how we perceive and feel about that product – affecting our perception of Taste.

For example, Biggs, Juravle & Spence (11) demonstrated that ginger biscuits eaten from a plate with a smooth finish versus the same biscuits eaten from a plate with a rough sandpaper finish were rated differently. The reported strength of ginger taste was accentuated by the rough feeling of the plate in the hands. Given that we often hold a pack in-hand at the first-moment-of-truth in the supermarket OR the second-moment-of-truth when we consume – the ‘feel’ or texture of the pack substrate has the potential to sub-consciously influence our product perception (and future purchase intent).

For example, even in a category as seemingly devoid of taste like bottled water, the work of Krishna & Morrin (12) demonstrated how the same water can still be described as ‘better quality’ when consumed from a sturdier container as opposed to a flimsy plastic cup.

The learning is clear that careful consideration should be given to any potential switch in packaging format or substrate. Our own work at Walnut Unlimited has revealed the challenges involved when light weighting glass bottles in the beer category. The sentiment was laudable i.e. providing a lighter carbon foot-print when it came to weight, transport and distribution costs. However, an unintended consequence was an associated drop in quality perception associated with the lighter weight bottle – especially noticeable when most of the liquid had been consumed.

Understanding the role of Touch and texture is therefore key as it has many implications for product and packaging design – very pertinent in the current climate where manufacturers seek alternative, sustainable and more environmentally friendly pack-options.

In conclusion…

Our perception of Taste in the role of product development and sensory testing is much more complex than it at first appears. Our associated product perception(s) go way beyond just the quality of the ingredients in the food that we place in our mouth.

At Walnut Unlimited we understand that to develop a product that consumers truly LOVE – there needs to be a sympathetic, holistic coming together of Sight, Sound and Touch – as well as Taste. And all that before you even begin to overlay the context of brand, experience and context!

Title: George Bernard Shaw; ‘Man and Superman’ (1903)
2. Heston Blumenthal; ‘Gastrophysics’ by Charles Spence (2017)
3. Daily Mail:
4. Gallace A, Boschin E & Spence C; ‘On the taste of “Bouba” and “Kiki”: An exploration of word-food associations in neurologically normal participants.’ (2011)
5. George H Van Doorn, Dianne Wuillemin and Charles Spence; ‘Does the colour of the mug influence the taste of the coffee?’ (2014)
6. Zellner DA & Durlach P; ‘Effect of Color on Expected and Experienced Refreshment, Intensity, and Liking of Beverages. The American Journal of Psychology.’ (2003)
7. Spence and Zampini; ‘The Role of Auditory Cues in Modulating the Perceived Crispness and Staleness of Potato Crisps’; Journal of Sensory Studies (2004)
8. The Grand Cork Experiment (2017):
9. Jean Anthelme Brillat-Savarin; ‘The Physiology of Taste’, Courier Corporation (2012)
10. Stevenson RJ, Prescott J & Boakes RA; ‘Confusing Tastes and Smells: How Odours can Influence the Perception of Sweet and Sour Tastes.’ (1999)
11. Biggs L, Juravle G & Spence C; ‘Haptic exploration of plate ware alters the perceived texture and taste of food’ (2016)
12. Krishna A, Morrin M; ‘Does Touch Affect Taste? The Perceptual Transfer of Product Container Haptic Cues’ Journal of Consumer Research (2008)

Meet the Author: Crispin Boon
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