Food and the Senses (Part 5)

In Part 4 of FATS, we saw how appearance greatly affects our eating experience. Over the rest of the month, we examined the visual aspect of food, mostly from an aesthetic viewpoint and this week, we we will examine the psychological side. We already talked a little bit about it in our Culinary Colours article. This time, we will delve deeper and see how such tactics can be used for commercial gain, and then segue into the next sense in our compendium.

An important tactic often used by restaurants is the Delbeouf illusion, which basically works this way: If there are two similarly sized circles, each surrounded by another circle, one large and one small, then the circle enclosed by the larger circle appears to be smaller than the one enclosed by the smaller circle, although they are both of the same size.

As a result, if a dish, especially a main course, is served on a large plate with lots of negative space around it, it looks smaller in size than the same dish, had it been served on a dish that just accommodates it. This illusion is so convincing that people actually feel less full when eating mains out of larger plates, giving them the impression that there is still room for dessert. This tactic is advantageous in any restaurant where you pay based on what you order. On the flip-side, all-you-can-eat buffets usually keep smaller plates, so that people get a false feeling of fullness despite not eating as much. Using smaller plates can also help weight-watchers control their portion sizes.

A different tactic is used to achieve a similar result when it comes to drinks. It is seen that beers served in curved glasses are usually finished faster than those served in straight sided mugs. This is because the brain judges how much we drink based on the height or level of liquid in the glass. With curved edges such that the top is wider than the bottom, people find it difficult to pace their drinking. When the glass is half-empty, more than half the drink has already been consumed. But it is difficult to keep track and people tend to finish their drinks faster. The same applies for drinks served in martini glasses. Hence, people tend to order more drinks, which translates to more profit for the restaurants.

The fallacy that the brain judges volume of a liquid by its level in the glass also manifests as the vertical-horizontal optical illusion: People consistently perceive equally sized vertical lines as longer than horizontal ones. As a result, we finish drinks in tall skinny glasses quicker than short stubby ones, and tend to pour more into shorter glasses. So, if you’re not planning to get drunk, choose the skinny glass.

We don’t often consider sound as an integral part of our eating experience, but think again. We love the hissing sound of a sizzler platter as it appears smoking hot on our table, we love, and some of us love watching ASMR videos of people eating stuff, ranging from the slurpiest of ramen to the crunchiest of potato chips.

Which brings us to our main topic when it comes to sound: Crunch. It is no mystery that we love crunchy foods; nay, we crave it. There are many reasons for it. Some of these are downright Pavlovian, where we associate crunch with freshness, which is good for us (think apple) or fattiness, which makes us feel good. (think potato chip). Crunch is therefore, rather ironically, associated with two contrasting aspects of food. But our brain cannot distinguish between that and remembers the simple formula, crunch = good.

Scientists speculate another reason for our affinity to crunchy foods, something that stems from a far less appetizing root. Early man was a hunter, and crunching down on animal bones was a part of the eating ritual. This animalistic behaviour might also explain why we adore crunch.

Food sounds originating from inside our mouth are not heard like normal sounds. Just like smell has two routes of entry into the nose, from outside via the nostril and from inside the mouth via retronasal olfaction (read FATS 3 for more), sound too has two doorways. The usual route is from outside via the ear canal, eardrum and middle ear. Sound, however, can also travel through bones of the skull to directly stimulate the inner ear, bypassing the above route. There are very few sounds which we experience from inside our mouths, and that is why food sounds are special.

Heston Blumenthal’s iconic “Sounds of the Sea” dish is based on the principle that certain sounds can actually heighten the flavours of a dish. The dish comprises elements of seafood like oysters, clams and sea urchins, and is served with an iPod in a conch shell, which plays sounds of the seashore. Diners are instructed to eat the dish while listening to the sounds. And apparently, it makes the flavours pop: the oysters taste brinier, and the overall flavour feels more “seafoody”. It has to do with psychological associations. The sounds trigger memories of visits to beaches, which heightens our appreciation of the seafood, making them taste fresher.

Sound is perhaps the most neglected of senses when it comes to eating, but eating would not be the same without it. In our next part, we will take a look at the fifth sense: touch.