healthmedicinet

One of the most pervasive claims to be found in the food science literature, as well
as in the plethora of press articles written about food and flavour, is that somewhere
between 75–95 % of what we think of as taste (i.e. as coming from the tongue) is actually
transduced by the olfactory receptors in the nose instead. Just take the following
as a representative example: ‘If people are asked to select which sense they find
least important, the sense of smell is routinely regarded as the least important of
the five’, according to Martin (3], p. 60). He continues as follows: ‘It is, in fact, responsible for 80 percent of
food flavour, a fact that is largely unknown and elicits a degree of disbelief’. Now,
as stressed by Spence 4] recently in this journal, delivering a precise, quantitative figure concerning olfaction’s
relative contribution to multisensory flavour perception may not be possible, especially
given the difficulty associated with trying to define flavour in the first place 5]. Nevertheless, that said, what the majority of contemporary researchers do broadly
seem to agree upon is the fact that it plays a dominant role in flavour perception,
not to mention olfaction’s role more generally in our enjoyment of food and drink
(and in the setting of flavour expectations). Given such agreement amongst researchers,
the questions that we wish to address here are: (1) How is such knowledge being incorporated
into, and hence changing, contemporary culinary practice? And (2) are there any dangers/limitations
associated with this approach to augmenting the experience of dining?

Orthonasal olfaction¹
is perhaps the most important sense (along with vision) in terms of setting our expectations
about a dish (and building-up our anticipation; see 6] for a review). However, that said, oftentimes the way that the dishes are served
in the restaurant, or home dining environment (think microwavable processed meals),
simply is not optimized to make the most of the olfactory element in a dish 7], 8]. Indeed, one point to draw attention to here concerns the difference between those
meals that are cooked at home (excluding microwave and other ready meals of course)
and a restaurant meal in terms of the surrounding smell/smell of the environment.
When cooking at home, it is likely that the food and cooking smells will play a role
in helping the diners to anticipate and expect the flavours to come. This will likely
also help to get their saliva going in preparation of the delivery of the food. In
a restaurant, which is separated from the dining area (and/or when coupled with a
good extraction system), such aromas cannot play this role (albeit this largely being
an intentional decision since the diners will be eating different things at different
times so ambient smells may be distracting). Thus, while the cloche in some sense
traditionally played the role of trying to recreate these aromas at the table, as
this form of silverware steadily moves further and further out of fashion (and with
little sign of ever coming back into fashion), one might consider whether the various
new methods of delivering orthonasal stimuli discussed in this article are not perhaps
being used to try and make up/compensate for this? While this might be a part of the
story, as we will see below, there is actually a lot more going on here in terms of
using aromas and scents to trigger moods, emotions, memories, nostalgia etc. (see
also http://www.ritzcarlton.com/en/Properties/Berlin/Dining/Fragrances/Default.htm).

Of course, beyond the orthonasal hit of aroma we get on first sniffing a dish, volatiles
are going to be released during the very act of consumption too (and experienced retronasally
9], 10]). As such, one might want to ask whether orthonasal olfaction really does play such
a dominant role in terms of setting our subsequent flavour experiences. We would argue
that it does, since orthonasal olfactory cues give rise to ‘flavour expectations’
that, in turn, anchor the subsequent flavour experience (see 6], 11]).

Capturing aroma

Looking back, one’s mind might well be drawn to the cloche, the silver dish cover
found in many a very traditional European restaurant that helps a dish to retain its
heat on its way from the kitchen,²
until the more-or-less theatrical ‘reveal’ at the table (see Fig. 1). Although rarely mentioned, such a piece of serviceware presumably also functioned
to keep the aromas of the food trapped under the hood until the appropriate moment.
It is perhaps worth noting that in today’s climate of plating for the eye (see 12] for a review), what the cloche delivers in terms of surprise (and tradition; the
cloche apparently going out of vogue with traditional ‘silver service’), it loses
in terms of eye (or visual) appeal. The fact that the dish is hidden from the diners’
view until the very last moment is perhaps not the ideal way to retain a dish’s aroma
in today’s image-obsessed age (the terms gastroporn, or food porn, come to mind here).
Furthermore, it may also be important to bear in mind the latest findings highlighting
the importance of the correct orientation of the plate in the restaurant to how much
the diner enjoys their food and how much they would be willing to pay for certain
dishes 13], 14]. Obviously, it is going to be hard for the waiter to get the precise alignment of
the dish right without being able to see the food itself when laying the cloche-covered
plate before the diner. What is more, nowadays, the very sight of the cloche in the
dining room is unavoidably associated with a certain sort of traditional restaurant,
an association that does not necessarily gel all that well with the contemporary restaurant
landscape.

Fig. 1. The restaurant cloche. Not only does it help to keep the food warm, while maintaining
an element of surprise, it may also prevent the dish’s aroma from being lost on its
way from the kitchen to the dining table [Image from http://cocolejour.blogspot.co.uk/2012/02/giverny.html]

If the olfactory element is as important to the diner’s enjoyment of a dish as the
scientists and media would have us all believe (see 4] for a review), one might expect that chefs would be designing their food experiences
to make the most of the olfactory component. Indeed, one obvious solution here is
just to simply concentrate the aromas of the dish itself, and that is certainly what
some chefs are doing. As Nassauer 15] noted recently, “Restaurants are adjusting recipes to make aromas more concentrated
and pleasant.”³
Though, quite how the restaurants were going about doing this was not made clear in
the newspaper report itself. In this article, though, we are going to take a closer
look at some of the more innovative ways in which chefs and culinary artists have
been playing with accentuating the olfactory component of the dining (and drinking)
experiences that they provide to their customers, whoever, and wherever, they might
be.

As we will see below, the last few years have seen the emergence of a number of innovative
solutions to the delivery of an enhanced olfactory element to the table: Everything
from aromatic plateware and aromatic cutlery to atomizers (to spray aroma over the
meal, and as we will see, possibly over the diner as well), digital olfaction (involving
both AR and scent-enabled plug-ins) and smell-enhancing attire as well—all of it has
made an appearance somewhere, be it restaurant, experimental dinner or science lab
in recent years.

Designing dishes to enhance the olfactory hit

The ‘smoking’ cloche

One intriguing dish that can, in some ways, be seen as a modern take on the traditional
silver version comes from chef Jozef Youssef’s dining concept Synaesthesia (see https://kitchen-theory.com/). In this case, a bowl of corn risotto, sous vide guinea fowl, miso-cured egg yolk
and chive powder is placed in a smoke-filled clear plastic bag in front of each of
the diners sitting around a long table (see Fig. 2). The chef would emerges from the kitchen and dramatically slice through each bag,
in turn, using a sharp knife. As the bag is sliced open, the smoky aroma inside is
suddenly released. At the same time, the plate of food is itself revealed visually
to the diner through the mist. After this olfactorily enhanced ‘reveal’, the chef
then carefully dribbles⁴
a little dark and aromatic sauce (guinea fowl and shiitake jus) over the dish. Only
then is the food ready to eat. In this case, notice how the sealed bag in which the
dish is presented not only preserves the smoky aroma for the benefit of the diner’s
nostrils but also helps to smoke the food (thus serving a functional purpose, as well
as bringing a memorable,⁵
and quite possibly theatrical, element to the proceedings).

Fig. 2. ‘Born in Papua New Guinea’. A dish of guinea fowl, sweet corn risotto, miso-cured
yolk served in a bag served by chef Jozef Youssef, as part of the Synaesthesia dining concept. The bag is filled with a smoky aroma in the kitchen and brought to
the table as shown. After the bagged dishes have all been placed on the table, the
chef emerges from the kitchen, slices open the bags with a knife and drizzles some
dark sauce onto the dish

Olfactory-enhanced plateware

In fact, in recent years, a number of chefs around the world have been experimenting
with aromatic plateware. Many of the most innovative examples in this space have emerged
from chef Grant Achatz’s Chicago kitchen, Alinea (https://website.alinearestaurant.com/). In one case, a bowl of food is placed atop a larger dish containing hyacinths in
front of the diner. The waiter would then pour hot water over the flowers at the table
in order to release their scent prior to the diner consuming the dish. Notice once
again the targeted delivery of scent at the table. In another distinctive example
of Achatz’s creative use of scented plateware, the waiter would first place an air-filled
pillow in front of the diner and then carefully place an oversized bowl of food on
top of it (e.g. an English-peas-and-ham preparation; 16]). As the diner interacts with their food, the pillow slowly starts (perhaps unexpectedly
for the diner) to release a stream of lavender-scented air. Here, while the food itself
is undoubtedly worthy in its own right, it is the integration of the dish with the
aromatics of the ‘plateware’ (and the ensuing spectacle, not to mention surprise)⁶
that once again helps to deliver a truly memorable multisensory dining experience.

One thing to note here is how the orthonasal aroma is sometimes used to evoke memories
in the diner. Here, one can think of Achatz’s use of burning oak leaves, designed
to evoke memories of childhood and served with pheasant, shallot, and cider gel 17], or chef Heston Blumenthal’s use of the scent of the sweetshop to remind diners of
pleasant memories from their childhood (and perhaps to induce a sense of nostalgia).

Another intriguing olfactory example comes from design studio Blanch Shock (http://blanchandshock.com/). They serve duck with Jerusalem artichokes and melilot on a ‘plate’ of charred chestnut
wood. In this case, it is the charring of the plateware itself that helps to give
the dish such an intense aroma (see Fig. 3). Something very similar has been going on at Noma (http://noma.dk/), the world-famous restaurant in Copenhagen (and voted the world’s best for 3 years
over the last decade). For a while, diners would be served a dish of two small quail
eggs sitting atop a bed of smoking straw 18]. Notice how what all of these diverse examples have in common is the use of the plateware
either to capture and retain, or else to deliver, an enhanced aroma hit direct to
the diner’s nostrils. Another increasingly popular approach to delivering an additional
olfactory component comes from those who have been experimenting with aroma-enhancing
cutlery.

Fig. 3. An example of olfactorily enhanced plateware. A Blanch Shock dish served on a burnt piece of wood [Reproduced with permission of Josh Pollen,
Blanch and Shock, London]

Olfactory-enhanced cutlery

In recent years, various individuals and companies have developed a range of novel
designs for cutlery; designs that are capable of providing an extra olfactory component
to every fork or spoonful of food. Louise Bloor, of the Fragrant Supper Club in London
(http://www.louisebloor.com/), for example, uses wooden forks whose handles her diners are encouraged to scent
with a range of aromas. Just imagine yourself, for example, eating a plain ice cream,
with a wooden spoon that has been scented with raspberry or bergamot essential oil.
A slightly more high-tech version of essentially the same idea comes from Canadian
company Molecule-R Inc. with their ‘Aromafork’ (see http://www.molecule-r.com/). In the latter case, the diner (or cook working the kitchen) is supposed to use
the pipette of ‘liquid aroma’ provided to apply scent to a small piece of blotting
paper inserted into the mid-section of the cutlery (see Fig. 4).

Fig. 4. The ‘Aromafork’, by Molecule-R Flavors Inc. The fork is designed to add an aroma (such
as lychee, almond, jalapeno or wasabi) to food (Figure reprinted from 19])

The media coverage around this, now commercially-available, range of cutlery has focused
primarily on the home cook who just so happens to have forgotten to add a key ingredient
to whatever dish they happen to be creating (e.g., see 19]). For us, though, it is the opportunity to design enhanced olfactory-dining experiences
that such cutlery might offer that would seem so much more intriguing than merely
making up for the chef’s absent-minded mistakes. Currently, the Aromafork comes with
21 different flavours, including chocolate, vanilla, lychee, basil, etc.⁷
One thing the company seems to have forgotten, however, is the importance of matching
the knife and fork—as thus far only forks are provided. While there is obviously little
need to scent the knife itself (since it rarely comes close to the mouth, at least
not in polite company), it is normally deemed desirable to have one’s cutlery match.⁸
Over in Australia, Elizabeth Willing has also designed a set of porous ceramic spoons
that are capable of releasing aroma (see Fig. 5).

Fig. 5. Set of porous-handled ceramic spoons designed by Elizabeth Willing. Once again, the
idea here is that essences can be added to enhance the dining experience; the suggestion
being that diner guests could then experience a bowl of vanilla ice-cream with each
of the three spoons [Source: Reproduced by permission of Elizabeth Willing]

It should, though, be noted that the design solutions here need not be especially
high-tech; think only of inserting some fresh herbs into the handle of one’s cutlery
as, for example, done with the sprig of fragrant thyme inserted into the curly wire-handled
cutlery used at Moto in Chicago (http://motorestaurant.com/) when serving ‘flat’-ware with Toro and Caviar (see Fig. 6) (Flatware, a North American term for eating utensils such as knives, forks and spoons,
which can also be used to describe relatively flat dishes such as plates and saucers).
Similarly, designer Luki Huber created a spoon for the elBulli restaurant that had
an integrated clip in the handle to allow the fresh herbs to be clipped just next
to the bowl and the spoon, thereby once again providing a complementary aroma with
each and every spoonful that the diner takes. And before moving on, we should perhaps
give a nod to the shrimp skewered on a vanilla pod from star-chef Achatz at Alinea. This can also be considered as constituting a kind of organic cutlery (see 20]; though, it is worth remembering here that one really needs to crush or rear the
vanilla pod in order to really release the most powerful aroma hit 21]), as can the stick of cinnamon bark that would greet the diner at the end of the
meal—the latter fragrant utensil used to deliver a tempura of caramel with Meyer lemon
and cinnamon sugar. Note also how in all of these latter cases, the use of real herbs
and spices to deliver the desired aroma to the diner’s nostrils obviously also helps
promote the authenticity of the smell through the eyes of the diner (see below).

Fig. 6. Aromatic cutlery served at Homaro Cantu’s Moto. (Source 14])

Meanwhile, the chef-in-residence here at the Crossmodal Research Laboratory in Oxford,
Charles Michel, has been known to serve his signature ‘Kandinsky on a plate’ dish
on a painting canvas 22]. Naturally enough, therefore, he sometimes gives his diners a wide-bodied paintbrush
to tackle the dish with (after giving the brushes a good wash, of course). On occasion,
the chef would scent the bristles with truffle, or basil, oil. In this way, a very
textured and aromatic impression can be delivered with each and every mouthful—a most
memorable multisensory tasting experience, to be sure.⁹
Crucially, the aroma tends to get stuck in the bristles near where they are attached
to the brush handle and hence an orthonasal olfactory input can be provided to the
diner’s nostrils mouthful after mouthful.

Interim summary

In this section, we have seen a diverse range of examples of aromatic plateware and
aromatic cutlery. Clearly, a number of chefs, culinary artists, and designers have
risen to the challenge of adding an additional olfactory element to the food that
they choose to serve in the restaurant and experiential dining context. Some of the
design solutions in this space also convey visually a certain visual appeal, and may
convey notions of authenticity, think the vanilla pod or sprig of herbs mentioned
above.

One other design solution that should be mentioned here, that achieves the same result
though does not quite qualify as cutlery, comes from those culinary artists who spray
aromatic scents on people’s wrist before giving their audience/diners something to
eat. One intriguing example of this approach comes from Caroline Hobkinson (see http://www.stirringwithknives.com/). She encourages people to eat a strawberry with their hands after having sprayed
their wrist with the scent of black pepper. Meanwhile, we have heard of others (linked
with Johnnie Walker Red Label) who in 2015 have been offering scented moustache wax
for their more hirsute guests (e.g., at Huckle the Barber in East London) to enhance
the taste of whisky (e.g., see http://www.dailymail.co.uk/femail/food/article-3152363/Johnnie-Walker-experts-create-world-s-whisky-moustache-wax-enhances-flavour-drink.html). In the next section, we are going to take a closer look at one of the other popular
routes to delivering an extra aromatic hit at the dining table, namely the atomizer
and dry ice.

Atomizers

Augmenting the olfactory component of dining by means of an atomizer provides a cheap
yet effective means of delivering an additional olfactory hit to diners. One of the
first to suggest such an approach was the Italian Futurist F. T. Marinetti back in
the 1930s. His recommendation was that meals should be eaten “to the accompaniment
of perfumes . . . to be sprayed over the diners” 23], 24].¹⁰
Diners nowadays would likely protest though should their waiter suddenly start spraying
them with perfume during the course of a meal. However, using an atomizer to spray
the scent of lavender over the food, specifically an oyster dish was certainly one
of your first author’s earliest memories of dining at The Fat Duck restaurant in Bray nearly a decade ago 25] (that said, though, your author does not remember any explicit link being made back
to the Futurists).¹¹

One other example worth mentioning here comes from the chilled citrus soup that was
served at chef Cantu’s Moto restaurant in Chicago (before the chef’s untimely death 26]), the dish being finished off at the table with a little togarashi mist being sprayed
over the bowl. ‘This is my favorite part of the meal’ said Cantu, ‘I get to pepper-spray
our guests’ 27]. Meanwhile, chef Youssef also utilized an atomizer to deliver the scent of saffron
(Saffronel) over the Miso veloute with poached langoustine, tofu and corn dish at
his Synaesthesia dining concept in 2015 (see https://kitchen-theory.com/). In this case, the use of the atomizer helped to deliver the same olfactory hit
as using actual saffron in the dish, but at a fraction of the cost of the real thing
(bear in mind here that saffron is, weight-for-weight, currently more expensive than
gold; 28]). Meanwhile, for the Kaiseki menu in 2014, chef Youssef created a matcha tea aroma ‘cloud’ which was served in
a goblet containing a sake, aloe vera and tapioca cocktail. A number of culinary artists
have also been exploring the use of atomizers to add fragrance to a dish 29].

Dry ice diffusion

One particularly impressive example of the use of aroma poured over dry ice to create
a fragrant smoky mist comes from Grant Achatz. The diner is presented with a cauldron
filled with seaweed bubbling and smoking from the dry ice; when the waiter opens up
the caldron in front of the expectant diner, the latter is greeted by the sight of
a scallop sitting inside its shell placed atop seaweed. More importantly, though,
a wave of citrus-scented aroma rises up to fill the diner’s nostrils. This is, once
again, both a visually dramatic and olfactorily effective means of releasing fragrance
to accompany a dish. The Fat Duck amongst many other restaurants has also used this
approach. Blumenthal uses dry ice diffusion very effectively with the Jelly of Quail with Marron Cream and Oak Moss dish (see Fig. 7). As one commentator describes the dish during its recent appearance in Australia:
‘This is one of the most visually exciting dishes: You have scented dry ice billowing
from below a serving tray that looks like a patch of grass. You are getting the smell
of the forest, the earthiness of the truffle and the taste of moss before you even
get near eating the birds and fish that live here.’ 30]. For the Nattura menu served in 2014, chef Jozef Youssef used dimethyl sulphide and dry ice diffusion
to recreate the aroma of sea air, while serving with a marinated crayfish, seaweed
and green bean amuse bouche. Here, one can also think of the layering of aromas—so
there may be an ambient background aroma to a dish and then the foreground orthonasal
aroma closely followed by the retronasal flavour of the dish itself. There are also,
of course, some great smells that one simply would not want to eat. As chef Grant
Achatz of Alinea fame puts it ‘We’ve done firewood ashes, we’ve done leather, we’ve done grass, …There’s
a lot of smells that you can’t necessarily consume. You’re not going to go out and
chew on a baseball glove. But, in a lot of ways, a lot of smells that aren’t necessarily
edible smell good, and they remind you of certain aspects of food. So making those
associations with what smells good or smells a certain way and pairing that with actual
edible ingredients is one avenue that we take creatively.’ (quoted in 17]).

Fig. 7. The Jelly of Quail with Marron Cream and Oak Moss dish served at The Fat Duck [Image from https://salonlaurel.files.wordpress.com/2010/05/wk-ap044_fat_du_g_20090312164550.jpg]

Another device that is used by a number of chefs and molecular mixologists to create
a dry ice vapour flavoured with any ingredient that happens to be inserted into the
device is the ‘cloud pour’ (see http://www.chillistick.com/cloudpour.html). Chef Youssef often uses the cloud pour. So for example, in his most recent menu,
Mexico, one of the dishes Memories of Oaxaca, consists of an Epazote (Mexican herb) cloud poured onto a hominy corn and shellfish
soup. In an earlier concept Kaiseki, a wheatgrass cloud was poured over a sake, aloe Vera and tapioca cocktail. The Hind’s
Head gastropub in Bray also sometimes uses the cloud pour as a safe means of working
with liquid nitrogen (see https://www.facebook.com/hindsheadbray/posts/367265300060086; http://www.chillistick.com/news/michelin-restaurant-loves-our-cloud-pour.html). Meanwhile, for those flying out of Heathrow’s Terminal 2, ‘Cloud Pourer’ cocktails
are also available at Blumenthal’s The Perfectionists’ Café (see http://www.hot-dinners.com/Gastroblog/Test-drive/heston-at-heathrow-we-test-drive-the-perfectionist-s-cafe).

The rotary evaporator (https://en.wikipedia.org/wiki/Rotary_evaporator) also deserves a mention here. This is a device that provides a useful means for
many kitchens to extract natural aromas from almost any substance. It was, for instance,
used to great effect in the dark chocolate dessert served by chef Jordi Roca. Distilled
coco bean essence created by use of the rotary evaporator enabled the chef to create
a completely white sorbet that nevertheless still delivered a rich dark chocolate
aroma to those lucky enough to try the dish 31].

Interim summary

The delivery of fragrance via an atomizer, liquid nitrogen or dry ice is not uncommon
nowadays, at least not in a certain kind of modernist restaurant. Such approaches
not only help to add an element of theatre/surprise to a dish, they can also be used
to ramp up the olfactory hit delivered by a dish, oftentimes using a fragrance that
may be different to, but hopefully complement, the dish itself. Of course, here one
might be tempted to ask why bother? Why not simply apply the aromatic component to
the food itself? Well, on the one hand, the atomizer/liquid nitrogen diffusion route
can be used to deliver a wonderful orthonasal hit, while avoiding any unpleasant flavour
(i.e. taste and/or retronasal smell) that can be associated with certain foods/flavours.
Here, just think of vanilla which smells great, but tastes horribly bitter if you
bite into a pod. It can also be used to deliver the aroma of other culinary elements
that may be prohibitively expensive in their own right (think saffron or truffle).
Perhaps more interesting, though, the addition of an extra olfactory element to a
dish can also be used to help add an element of theatre to the proceedings (something
that a growing number of chefs are increasingly interested in dishing up).

What is also interesting are those occasions when the chef augments the inherent aroma/flavour
of the dish in order to try and create some sort of olfactory figure/ground segregation
32]. One example of such an approach comes from the ‘Messi’s Goal’ dessert that was served
at El Celler de Can Roca in Spain 33]. This dish, a tribute to the famous football player from Barcelona FC, would arrive
at the table as half a football covered with artificial grass that has been perfumed
with the smell of freshly cut grass. While the smell of freshly cut grass undoubtedly
creates an appropriate olfactory backdrop for the dish, there are likely few diners
who would want to eat the stuff. It is, then the use of olfaction as scene-setting,
or background to the flavours of the dish itself, which hopefully sit foregrounded
centre stage in a diner’s consciousness.¹²
Of course, those chefs who deliver a single-sitting tasting menu can fragrance the
entire dining room. One such chef who has uses this approach is Paul Pairet in Ultraviolet
in Shanghai 32].

At the opening of the Synaesthesia pop-up, the Marinetti Cubist Vegetable Patch dish (sesame and coffee marinated paneer cubes, mushroom crisps, pearl barley, crispy
bacon, maple cream) was served with three pots of scented water which correlated with
the ingredients in the dish. The guests were instructed to drop dry ice pellets into
each pot to release the scent and, in turn, heighten the flavour of that particular
element (or flavour; tarragon, pomegranate and then smoked bacon) in the dish. Meanwhile,
one of Heston Blumenthal’s dishes that is in some way similar (and that apparently
works on around 85 % of people) is his two-flavoured cinnamon/vanilla ice cream (see
Fig. 8). Just imagine two squeezy bottles, one with cinnamon sticks the other with vanilla
pods. Sniff one bottle for a few seconds and the brain adapts to that aroma. Hence,
when you take a taste of the ice cream it should taste more strongly of the other
flavour. If you repeat the procedure but this time sniffing the other bottle then
the flavour of the ice cream switches. This is an entertaining use of orthonasal olfaction
to change the perceived flavour of a dish. It can be argued that such dishes help
illustrate how something unique can be brought to a dish by separating and playing
with the olfactory elements. In the next section, we will take a closer look at the
potential use of technology to deliver an added olfactory element to a dish.

Fig. 8. Two-flavoured (cinnamon and vanilla) ice cream by Heston Blumenthal [Image from http://sageappliancesclub.co.uk/article/cinnamon-and-vanilla-ice-cream]

Augmented (digital) smell

Some researchers, especially those in the human-computer interaction community working
out of the Far East have been investigating various ways in which to digitally deliver
an additional olfactory element to food experiences (see http://digital-olfaction.com/). So, for example, Narumi and colleagues 34] developed one such prototype multisensory display that, at least according to the
developers, could help to change the perceived flavour of food by means of visual
and olfactory AR. AR is defined as an experience of a physical, real-world environment
whose elements have been augmented, or supplemented, by computer-generated sensory
input. In Narumi et al.’s case, the idea was that the device recognizes the digital
tag (e.g. a metacookie placed on top of the food) and then changes the visual appearance
of the food accordingly. At the same time, the appropriate aroma for the food that
the user can see via the headset is also released to enhance the ‘realism’ of the
situation (see Fig. 9). However, a quick look at the headset probably tells you all you need to know about
how soon you will be seeing such technology in the restaurant setting. Other scent-enabling
technologies look more promising though (see https://www.prote.in/en/feed/2014/04/sensabubble).

Fig. 9. Hmmmmm, tasty! Sometimes HCI researchers perhaps spend a little too much time thinking
about what is possible with technology and not enough time thinking about what is
actually likely to be applicable [Figure showing AR multisensory flavour display;
reprinted from 34], with permission]

In the future, it would also seem likely that there may be a role for the hand-held
technologies that one finds in most people’s pockets in augmenting the dining experience
too. Indeed, the last few years have seen something of an explosion of interest in
digital plug-ins (e.g. the Scentee; https://scentee.com/).¹³
Certain of these can already release specific food aromas; just take the following:
“Available scents include rose, mint, curry, jasmine, cinnamon roll, lavender, apple,
strawberry, ylang-ylang (a fragrant flower), coconut, and if you remember the fried
corn soup fritters at KFC Japan from earlier this year, the corn soup scent should
come as no surprise. There’s also a limited-edition Korean BBQ collection with two
meat scents and baked potato. Other scents are also in the works.” 35]. Currently the bubble-shaped Scentee (see Fig. 10) retails at around $5 in The USA and can deliver around 100 bursts of a fragrance.¹⁴
There are, though, a couple of potential limitations that will likely limit the uptake
of this kind of technology at the dining table, on the one hand, most commercial devices
can only release a single scent, obviously not ideal for a multi-course-tasting meal.
Furthermore, it can be difficult to simulate a suitably realistic aroma in certain
cases.

Fig. 10. Scentee: Digital smell. Will it one day be used to enhance the dining experience?
[Picture courtesy of Adrian Cheok]

Interim summary

Despite the media’s excitement, the various digital olfaction solutions that have
been launched thus far all have more the feel of proof-of-principle prototype (Narumi
et al.) 34], or ‘marketing gimmick’ 36] than genuine gastronomic intervention or godsend. Certainly, there has been little
evidence of such technology being incorporated into the serviceware of high-end restaurants
yet 20], 37]. If such wearable devices could be made more, well, wearable—think wireless and light-weight,
not to mention capable of delivering a variety of aromas—then who knows, perhaps they
might make an appearance at some restaurant one day. However, the current need to
make sure that there is some sort of QR code, or tag (i.e. metacookie), on the food
itself, obviously limits the mainstream utility of the AR technology, impressive though
it undoubtedly is.

Smell-enhancing attire

One other solution, that has both a more traditional (albeit niche) and a more modern
incarnation is the attire, or hat, that the diner might wear in order to enhance the
olfactory component of dining. The niche version relates to the way that some French
diners would traditionally have eaten ortolan, a rare bird of the bunting family with
an apparently exquisite aroma 38]. The bird is eaten whole, and was purportedly on the menu for ex-president Francoise
Mitterand’s final banquet shared with 40 friends shortly before his death in 1996
(see Fig. 11). According to Baxter, these thumb-sized birds were: ‘Kept alive until the last minute,
they were drowned in Armagnac, plucked, sautéed, and served in individual lidded pots
called cassolettes, which could only hold one or two birds. One ate them whole, including
legs, bones, and intestines (although the more fastidious left the head). Their aroma
was so delectable that, before opening the cassolette, diners draped napkins over
their heads, conserving every whiff.’ Notice how the napkin in this case serves to
capture all of the aroma of the dish, while at the same time removing vision during
the act of consumption. This will presumably have the effect of accentuating the diner’s
pleasure in their gastronomic experience. One might wonder whether removing vision
is especially appropriate here in helping to hide the perhaps unpleasant sight of
the whole bird. Notice, though, how the situation here is somewhat different from
all those who dine in the dark restaurants where no information about what is being
eaten is often provided, and where people rarely have anything good to say about the
taste/flavour of the food 20].

Fig. 11. A diner, with their napkin wrapped around their head enjoying the illegal pleasures
of an ortolan, a rare bird of the bunting family, served in France and which is meant
to be eaten whole. This was purportedly on the menu for ex-president François Mitterrand’s
final banquet shared with 40 friends shortly before his death in 1996 [Figure taken
from John Baxter’s, The perfect meal (38], p. 126)]

In a related vein, but in some ways less extreme, the final year project of one of
the students at an art/fashion college recently involved the creation of a range of
smell-capturing hats and caps for diners. Less extreme than the napkin example above,
these future fashion items still allowed the diner to see their food while at the
same time helping to funnel the aromas emanating from the dish towards the diner’s
nostrils. This kind of approach to enhancing the dining experience is reminiscent
of the headspace capture techniques that have been used for years, by companies such
as Givaudan in order to capture the flavours of unusual foods (e.g. 39]; see also 40]). A potentially much cheaper and more widely available attire solution here might
come from the nasal dilator.

Nasal dilator as flavour enhancement device?

One less glamorous, but potentially no less effective, means of enhancing a diner’s
olfactory enjoyment of a meal would seem to be to use The Breathe Right nasal dilator,
first marketed back in 1993 (as the Breathe Rightâ„¢ Nasal Strip; CNS Inc., Chanhassen,
MN). These off-the-shelf strips were originally introduced for use by sportsmen and
women; the idea being to place the strip on the bridge of the nose just above the
fleshy portion of the nostrils. The nasal dilator is supposed to exert a spring-like
action preventing the sides of the nasal vestibule from collapsing inward during nasal
inhalation. Scientific tests have revealed that resistance in the nasal airways is
reduced by as much as 30 % or more when wearing one of these devices 41]. Meanwhile, nasal imaging reveals a 25 % increase in airspace volume in the soft
anterior region of the nasal passage and an 11 % increase in the bony posterior region
42]. In the context of the present article, then, one might wonder whether the nasal
dilator could be used to enhance the dining experience, if olfaction is, as we are
led to believe, such a large part of the dining experience.

Over the years, a number of studies have provided results relevant to addressing this
question. For instance, Hornung et al. (43]; see also 42]) reported that wearing one of these strips led to olfactory stimuli being rated as
significantly more intense (by 16.7 %) than was the case for those participants who
were not wearing one. Furthermore, those wearing such a device also show significantly
enhanced odour identification abilities (99 vs. 78 % correct identification, respectively,
at least according to the results of one test; 42]); those wearing a dilating strip were also able to detect odours at a significantly
lower concentration than those who were not.¹⁵

That said, the story appears to change somewhat when it comes to people’s evaluation
of actual foods. In one of the only studies of its kind, Raudenbush and Meyer 44] assessed the effects of wearing a nasal dilator on people’s ratings of the pleasantness,
intensity, and their sampling behaviours towards ten foods (that included chocolate
icing, butterscotch pudding, applesauce, peanut butter etc.) that the participants
(N?=?88) were encouraged to sample with a spoon. In this between-participants study,
participants wearing a nasal dilator did indeed rate the foods as more intense (1.59
points higher on an 11-point scale). That said, they also rated them as tasting less
pleasant (an 0.7 point difference on an 11-point scale in this case), than did those
participants who were wearing a placebo strip instead. What is even more striking,
those wearing the nasal dilator consumed 61 % less food.¹⁶
In this case, intensity was correlated with pleasantness and consumption, i.e. as
intensity increased, both pleasantness and consumption declined.

As yet, then, there does not appear to be any clear evidence in support of nasal dilators
being utilized as an aid to enhancing the dining experience. There is, though, perhaps
a question here about the use of commercial foods here. One can easily imagine how
the taste qualities of such products would presumably already have been optimized
for liking. Who knows, then, whether the results of Raudenbush and Mayer’s 44] study would have been any different had foods with a less intense aroma had been
used instead? One other thing to bear in mind here was that all of the foods were
removed from the fridge 30 min before serving. Obviously, a hot dish might well be
expected to deliver more of an orthonasal olfactory hit, and hence benefit more from
the nasal strip. Given the potential importance of the nasal strip as a potentially
cheap and simple means of enhancing the olfactory contribution to our anticipation
and enjoyment of the flavour of food, more research is still needed in order to confirm
just how generalizable these nasal dilator findings really are. It would be a shame
to miss a trick with such a seemingly simple solution here.¹⁷

A final example that is worth dwelling on for a moment here is the device that was
patented back in 1996 by Knight that was designed to enhance to the olfactory experience
of those suffering from some sort of olfactory deficit. According to Avery Gilbert
(8], p. 83), it resembled: ‘a double-ended turkey baster with the bulb in the middle
equipped with one-way valves. The user positions one end of the device over, say,
a bowl with chili, then squeezes and releases the bulb, and it fills with air. Now
the user inserts the other end in his nostril and squeezes again, forcing a bulb full
of chili-scented air up his nose.’ While this device was originally designed to help
those with limited olfaction, one could perhaps imagine how some culinary artist or
experience designer might think about utilizing such a device in order to give diners’
an enhanced olfactory hit of some delicious aromatic dish or another. It is, though,
only a relatively small step from capturing the aroma of a dish with such a device
through to the notion of eliminating the actual food itself, as we will see in the
next section.

Interim summary

In this section, we have seen a number of examples of scent-enhancing attire and scent-capturing
tools. Such solutions are currently more the domain of the arts student and of disability
aids than high-end cuisine. Who knows whether we will see any of these solutions appearing
in the restaurant one day soon. One important theoretical issue to bear in mind here,
though, relates to the phenomenon of perceptual constancy. Perceptual constancy refers
to the tendency that we have to perceive familiar objects and stimuli as having standard
appearance (e.g. size, shape, colour or loudness) regardless of any changes in the
sensory input. The result is that we tend to perceive objects/stimuli as it is, or
as it is assumed to be, rather than reconstructing an impression that accurately reflects
the actual sensory input 45].

Importantly, perceptual constancy operates in the olfaction just as it does in the
other senses. In one study, for example, Teghtsoonian and Berglund 46] had their participants sniff at one of two flow rates, one twice as great as the
other. The participants then had to make magnitude estimation judgments concerning
a variety of suprathreshold olfactory stimuli. Interestingly, and perhaps counterintuitively,
the dramatic variation in the subject-controlled flow rate exerted no influence whatsoever
on the perceived strength of the odorants. This null result was taken to suggest some
kind of size constancy mechanism, or invariance, operating in olfaction, with judgments
of odour intensity being made in relation to perceived vigour of sniffing. Teghtsoonian
et al. (46], p. 151) went on to conclude that: ‘It may be argued…that, even if flow rate is an
important parameter of the proximal stimulus for odour strength (discharge rate in
the olfactory nerve), information about sniff vigour may control its effect on the
perceptual response.’ That said, Le Magnen 47] found that threshold for the detection of eucalyptol odour was lower in those with
higher inhalation rate (see also Rehn 48] for similar results). The reason why it is important to consider the existence of
perceptual constancy in the olfactory modality is that it might, just possibly, minimize
the effectiveness of the nasal strips, and other olfactory-enhancing attire we have
come across in this section. While more research is undoubtedly needed on the topic,
the suggestion that emerges from studies of this phenomenon in the other senses is
that it should have less influence on perception for those stimuli that are less familiar
to us—think unusual flavours, rather than the widely-available commercial food products
used by Raudenbush and Meyer 44].

The olfactory dinner party: who needs to eat the food anyway?

Thus far, all of the examples we have seen have involved enhancing the olfactory component
of a meal, but, in all cases, food still formed part of the dish. Some chefs and culinary
artists have, though, been tempted to go even further. After all, if scent really
is 95 % of flavour (as some would have us believe; this at the upper end of the range
of percentages one finds in the literature; see 4] for a review), then one might wonder why not just cut the other 5 %, simply deliver
the aroma of the food and reduce the calorie count into the deal.¹⁸
Interestingly enough, people have been thinking about the notion of the pure olfactory
dish, or meal, for many years now. Some of the first suggestions along these lines
appeared back in 1930, and, once again, we have the Italian Futurist to thank for
making the suggestion. Just take the following:

In fact, in the ideal Futuristic meal, served dishes will be passed beneath the nose
of the diner in order to excite his curiosity or to provide a suitable contrast, and
such supplementary courses will not be eaten at all. (49], p. 43).

One also finds Evelyn Waugh in print in the same year speculating about something
seemingly quite similar in his novel Vile Bodies50]:

He lay back for a little in his bed thinking about the smells of food, of the greasy
horror of fried fish and the deeply moving smell that came from it; of the intoxicating
breath of bakeries and the dullness of buns… He planned dinners, of enchanting aromatic
foods that should be carried under the nose, snuffed and then thrown to the dogs…
endless dinners, in which one could alternate flavour with flavour from sunset to
dawn without satiety, while one breathed great draughts of the bouquet of old brandy.

The last few years have seen something of a resurgence of interest in the Futurists
and their crazy, wonderfully-inventive ideas (e.g. see 51], 52]). As such, there have been a number of dining events where the idea of the purely
olfactory dining experience (or at least the purely olfactory course) has been recreated
(e.g. see Fig. 12 for one such representative example 53]). In fact, given the nature of some of the Futurist’s recipes, sniffing the dishes
might well have been preferable to eating them anyway 51].

Fig. 12. ‘Aerofood’. A mylar balloon holding food scent, one of the dishes served at The Tactile
Dining Car, a participatory dining and performance installation held at the Flashpoint
Gallery, Washington DC, 9–24 September 2011. Source: Reproduced with permission of
banished? productions/Carmen C. Wong (and found in 50])

The idea of inhalable food has certainly become a lot more practicable in recent years
with the development of machines, and now commercialized devices, designed to deliver
vaporised food. For instance, American scientist David Edwards and French culinary
designer Marc Bretillot invented a gadget that they christened ‘Le Whaf’. This clever
little device transforms food into a cloud of flavour. First, the food, say a lemon
tart, is boiled down into liquid form. Next, the resulting mixture is strained and
transferred to a carafe. Then, ultrasound is used in order to transform the liquid
into vapour. Finally, one simply pours a cloud of lemon tart into a glass and sips
it with a straw (see the company’s website http://www.aerodesigns.com/ for a number of other instantiations of this concept).

The sorts of creations that the chef might come up with if using such a device were
highlighted at the launch party of Le Whaf in 2012. Massimo Bottura, from the Osteria Francescana (in Modena, Italy), prepared a canard’ à l’orange; Ben Shewry from Attica (in Melbourne, Australia) mixed four clouds from rice, rice vinegar, soy sauce and
ginger to create a surprising gaseous concoction. Meanwhile, chef Homaro Cantu from
Moto (in Chicago, USA) used some of the miracle berries of which he was so fond, together
with a handful of other ingredients including a mixture of hazelnut liquor and lemon
vodka, in order to deliver what was supposed to be the first breathable chocolate
cake. Bottura has taken the idea back to his restaurant in dishes such as his Parmigiano Reggiano in textures with Parmigiano cloud (see Fig. 13, 54]). Here, it is worth noting that a number of culinary artists have started to work
with edible inhalable/flavours as well (e.g. http://www.aliceandthemagician.com/blog/). One can deliver inhalable cocktails or drinks using the Vaportini (see http://www.vaportini.com/history.html). And taking things to a much larger scale, the notion of inhalable flavours has
recently been extended to a room-filling scale with the olfactory, or breathable,
Alcohol Architecture bar recently opened at Borough Market, London by the fabulous
Bompas Parr in London (http://concreteplayground.com/auckland/food-drink/drink/this-pop-up-bar-of-dreams-specialises-in-breathable-booze/; http://bompasandparr.com/projects/view/alcoholic-architecture1/).

Fig. 13. Parmigiano Reggiano in textures with Parmigiano cloud as served by Massimo Bottura at the Osteria Francescana in Modena, Italy (Figure taken from 54])

What all of these inhalable ideas lack, though, and what is presumably crucial, is
the oral-somatosensory element of stimulation while enjoying food. And, while the
inhalable dish or drink has a certain appeal, our gut feeling is that most diners
are going to feel a little short-changed if they were only given an inhalable meal!!
Inhalable drinks seem, if anything, like a more plausible route to take here, given
that we do not always drink for nutrition and sustenance. Consistent with this notion,
there has been a recent growth of breathable cocktails (e.g. http://cassandradaily.com/life/raising-the-bar/). Our bet, though, is that inhalable aromas and mists will work best when delivered
as a mist over a dish, or in a glass on the side to accompany it—i.e. enhancing the
consumption experience rather than replacing it.

On the authenticity of flavours

Finally, in this article, it is important to raise one potential concern about all
of these attempts to augment the olfactory component of a dish, be it through aromatic
plateware/cutlery or via atomizer or scent-enabled plug-in, Namely, ‘authenticity’.
Now, assuming that this augmenting of the orthonasal olfactory component of flavour
perception really works (as in, it is appreciated by diners), it does raise the questions
of the ‘authenticity’ of flavour. The worry here is that perhaps although our food
experiences can be enhanced in this way, might the diner not in some way feel tricked?
This kind of idea inadvertently presents itself as Jonathan Coutu, whose firm created
the olfactorily enhanced eating utensil, suggests in one interview that: ‘The initial
idea was to reinvent the traditional fork into an improved utensil that would trick
people’s mind by liberating an intense flow of aromas.’ (quoted in 19]), or take the text on the Aromafork website itself: ‘Trick your mind with aroma R-Evolution’19].

Of course, similar concerns about the artificial manipulation of aroma emerge in other
places too. Just take the example of adulterating one’s spirits or wines to give them
the appearance of something much more interesting/expensive (e.g. see the Whiskey
Element for one such example, 55]). Here, one is also reminded of the suggestion by Hervé This of a few years ago:
‘to add the aromatic molecule, vanillin, to a cheaper whiskey before serving it to
guests because vanilla is found in some more expensive whiskeys.’ 56].¹⁹
Issues of authenticity soon crops up when considering This’s enthusiastically-expressed
ideas around what he has christened ‘note-by-note cuisine’ (see 56]–58]). Now, assuming for a moment that the flavour experiences so-created are pleasant,²⁰
one is still left worrying about the authenticity of it all, and how much that matters
to the diner. According to This, note-by-note cuisine would allow us to recreate a
classic bottle of wine. But is that really what the wine expert is paying all that
money for? We think not, at least not always. Perhaps what the diner, or for that
matter drinker, is really after is an ‘authentic’ experience, rather than necessarily
caring all that much about the actual taste/flavour itself 59].

In the best-case scenario, perhaps it turns out like the placebo effect. That is,
even though you know that you are using a placebo, it can still work, at least to
a certain degree, and under certain conditions 60]. Maybe here the key thing distinguishing the augmenting of the olfactory element
of a dish in the modernist restaurant case and that described in the adulterated whiskey
(or should/could that read whisky?) case is the fact that the theatricality of the
performance in the restaurant draws the diner’s attention to the fact that everything
is not as it seems as far as the aroma is concerned. By contrast, the implication
in the spirits case is that the information would (or, at least, might) be hidden/disguised
in some way. As long as the diner/consumer is aware of what is happening, they can
make up their own mind about whether they like it, whether it was worth the price.

On the other hand, of course, one might simply ask whether all of our flavour experiences
are, in some sense, fake. As Khatchadourian 61] put it in an article for The New Yorker magazine: ‘The consumption of food flavorings is one of the modern era’s most profound collective
acts of submission to illusion.’ Thus, the conclusion here is that it is currently a little hard to predict how exactly
the diner/consumer will respond to the kinds of olfactory enhancement of flavour that
have been outlined here. Perhaps, it is part of the role of the modernist chef and
culinary artist to play in the space and figure out what works well, and more importantly,
what people are willing to pay for in terms of augmented eating experiences. In recent
years, the work of a number of designers and culinary artists can certainly be seen
as playing in exactly this space (see 20] for a number of examples).