June 10, 2024
One of the most important aspects of experiencing food or drink, “mouthfeel” is as elusive as it is essential.
When it comes to perfecting a food or beverage, certain qualities are difficult to quantify, personal preferences aside. “Mouthfeel” is one of these, and its unique ability to magnify or massacre the enjoyable quality of a given food experience is so undeniable it’s almost primal.
“Although our preferences change over time with culture and habit, the oral receptors and the physics behind mouthfeel haven’t changed much since we lived in caves and clubbed animals for dinner,” says Jenny Jonsson, Food Technologist at Tetra Pak. “In many ways, it’s more universally human than other factors, which can be more regional—like taste, flavour, or texture.”
“If you bite into a salad, you’re expecting it to be fresh and crisp – so if your tooth hits a piece of sand or grit, that’s really going to disturb your experience.”
Indeed, we all know the feeling of putting something in our mouths and experiencing immediate disgust, an overwhelming ickiness we can’t quite put our finger on. In such unfortunate moments, mouthfeel is often the culprit. It’s a quality that can be as elusive as it is desirable, and it’s often the essential element of a sip or a bite that makes or breaks the experience.
But even though most of us want silky custards, crunchy carrots, juicy fruits, and creamy purees, there’s nothing simple about the science of “mouthfeel.”
The quest for the perfect mouthfeel
Mouthfeel is often described as a combination of four qualities—structure, body, eating properties, and creaminess—but Jenny prefers to see it as a matrix, or an “area,” where numerous sensations meet.
The perfect mouthfeel, she explains, results from a symphony of factors – some more quantifiable, and others more ephemeral and subjective – which makes them difficult to examine in a vacuum or to isolate from one another. While some elements of mouthfeel, like the size of fat droplets, may be quite concrete and easy to measure, others like the psychological impact of taste, for example, are more difficult to quantify. That’s why mouthfeel is tricky mix that’s almost impossible to boil down to an algorithm or scientific measurement.
The dance of textures and flavours that create the perfect mouthfeel is a delicate balance, and the nuances of this sensation are as integral to a decadent treat as they are to a healthy snack.
"You don't choose to eat a food like cream cheese, for example, when you're just filling up your belly on the go," says Jenny. “That is a food people select for its rich, pleasing mouthfeel, something which makes them feel that they are eating something delicious and indulgent.”
The psychology of mouthfeel
One fascinating aspect of mouthfeel is how flavours and textures can deceive our senses. Including vanilla in a product, for example, can increase the perception of creaminess, even if there’s no cream in it. This is why food producers often add vanilla alongside another flavour to increase the indulgent experience of eating it, combining vanilla with strawberry in strawberry yoghurt, for example.
“The oral receptors and the physics behind mouthfeel haven’t changed much since we lived in caves and clubbed animals for dinner.”
But sometimes, our associations can get in the way of our enjoyment. According to Luciana Saboya, a Food Technology and Ingredients Expert at Tetra Pak, there is a certain magic in not knowing precisely why you like something – but that magic is also why, occasionally, experiments with mouthfeel can fail spectacularly.
“I recall a project aimed at creating a drinkable peanut butter,” she explains. “We crafted a drink using peanuts and cream, and we tried to keep it high in protein and low in sugar. But the feedback shocked us: While the texture, the product's essence, was spot-on, there was a crucial missing piece: the familiar flavour. Nobody liked it because it didn’t taste like what they thought peanut butter should taste like!”
Expectation is essential
According to Luciana, that experiment underscored that the essence of our preferences lies in a mix of factors. The texture must not only please but also harmonise with the flavour and the overall sensation—and the result is the mouthfeel. It's about how all these elements interconnect to deliver a cohesive experience that resonates with us on a sensory level.
“If you bite into a salad, you’re expecting it to be fresh and crisp – so if your tooth hits a piece of sand or grit, that’s really going to disturb your experience,” Luciana adds. “And if your rice pudding doesn’t have chewy particles of rice that interrupt the creaminess, you will also be disappointed.”
Expectation can also play an important psychological role in the regional differences in mouthfeel. In Northern Europe, for example, where most people regularly eat porridge, there is a much higher tolerance for the mouthfeel of fibres, which can be experienced as astringent, or bitter in a beverage. But in cultures where people expect something like a soy beverage to be smooth and milky, the fibre texture, no matter how subtle, would likely put people off the product.
When it comes to food replacements, like plant-based cheeses, the psychology of comparison is also essential.
“I work with a lot of plant-based cheeses, and when a customer comes to us in that case, they often say that the main quality they want to achieve is similarity,” says Jenny. “But there are many aspects of a given cheese that make us recognise and enjoy it. So how can we define and then capture the most important element of that experience?”
Measuring mouthfeel
The psychological impact of expectation and comparison, not to mention how flavour can actually transform our experience of texture, helps illustrate why mouthfeel transcends the realm of simple measurement. And yet, it can be done to some extent.
In controlled contexts, scientists use tribological instruments or sensors, plastic instruments meant to mimic the actions of chewing and the movement of the tongue, to evaluate physical interactions between food and the human mouth's surfaces.
“Cream cheese is a food people select for its rich, pleasing mouthfeel, something which makes them feel that they are eating something delicious and indulgent.”
By measuring the resistance, how the food changes in consistency, the degree of slipperiness, and other elements, scientists can attempt to quantify the aspects of mouthfeel in a standardised way. But as Jenny explains, these devices can’t be calibrated to human subjectivity, and product specificity is critical.
“There are definitely ways of measuring mouthfeel that are more objective,” Jenny says. “But we can never measure the full sensation a human mouth experiences. There are always so many different aspects to it – there truly is nothing like the human palate.”
Mouthfeel: the future of food experience
In an industry where the battle for consumers’ hearts—and stomachs—is won through nuanced experiences, mouthfeel is a frontier of innovation and creativity.
As we look to the future, mouthfeel will only become more important. It's a sensory journey that can define the success of a product, a culinary experience and an entire brand.
“Our customers can come to us with a certain need for a mouthfeel, and we can adapt the way we treat the food product to accommodate their wishes,” Jenny concludes. “If they tell us what they’re going for and what their most important parameters are, there’s no telling what we can come up with. That’s why it’s such an exciting area to work with!”
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