Every two weeks, select groups of diners have been coming together in London, UK, to be part of an audio-visual experiment to delve into ‘synaesthesia’, a neurological state where the senses are connected. People with synaesthesia claim to see colours when they hear sounds, or to link colour to flavour. In its early days, the word was applied to a very limited number of people but is now entering mainstream vocabulary, particularly in relation to food.
The meals are the brainchild of London-based chef Jozef Youssef, founder and chef patron of Kitchen Theory (KT), a collaborative project that brings together chefs and scientists to investigate the many facets of gastronomy and food science. Working with Youssef are psychologist Charles Spence and his team from the Cross Modal department at Oxford University, UK, together with neurologist Richard Cytowic and Sean Day, president of the American Synaesthesia Association. Spence explains: ‘I have been looking at the surprising link between the senses, such as, for example, that tastes have shapes and colours. And if you know that you can start “synaesthetically” conveying tastes without words.’
On the KT menu are seven courses, including The sight and sound of flavour and Four tastes. During the latter course, diners watch a video in which Spence asks them to label the coloured foods as sweet, sour, salty and bitter. ‘What we are trying to do with these dinners is to get people to experiment with the perception of colour in terms of flavour,’ explains Youssef.
Another of the courses is Bouba-Kiki, which sounds like an exotic beach resort but is in fact an ‘effect’, traditionally describing associations between the words Bouba, meaning soft, and Kiki, meaning sharp, and representing rounded or angular shapes, respectively. Sound symbolism has long been built into marketing, perhaps subconsciously. For example, Spence draws attention to the fact that brand names KitKat, Crunchie and Munchie are all wafer or biscuit-based, while the brands Rolo and Aero are softer, rounded products. For the synaesthesia meals, the results of which have not yet been pulled together, the Bouba-Kiki dish comprises two elements, one with a sharp, acidic taste and the other a more rounded flavour, which diners are asked to link to the words.
Spence recently led a study of over 400 people from China, India, Malaysia, and the US, who were asked to associate taste – bitter, salty, sour, sweet and umami or savoury – with shapes, ranging from ‘blobs’ to crosses, and textures. Cultural differences meant that taste patterns shown by participants from the four countries differed somewhat from one another but common factors emerged, including an association between the colour black, a cross shape, and a bitter taste. Meanwhile, a cloud shape and pink colour made people think of sweet things.
A recent product change by US foods company Kraft clearly demonstrates the link between shape and taste. When the shape of the chunks in Cadbury Dairy Milk bars changed from rectangular to curved, it caused uproar and endless complaints that the confectionary was too sweet. Yet the manufacturers were adamant that the chocolate formula had not changed, only the shape, backing the idea that sweetness is associated with roundness and bitterness with angularity.
For Spence, the idea that it is possible to alter the taste of a food simply by changing the shape in which it is presented is an exciting one. Both Youssef and Spence suggest that shape–flavour associations could be used to promote healthy eating, for example, by enabling manufacturers to reduce sugar levels by changing shapes to increase the perceived sweetness of a product.
Even bigger than the challenge to fight obesity is the question of how to feed the expanding global population in decades to come. And central to this problem is the enormous challenge of cutting food waste.
French physical chemist Hervé This, commonly referred to as ‘the father of molecular gastronomy’, pins hope on his ‘note-by-note cooking’, which builds dishes using collections of chemicals. ‘I don’t want to recreate anything; the proposal is to create new food,’ says This, who heads AgroParisTech’s molecular gastronomy group. When the idea for note-by-note cooking first came to This in 1994, even he thought it was ‘too provocative’. Now he is convinced that it is ‘the future’ and likens the process to using a synthesiser to create new music.
Armed with a range of flavour chemicals, together with plant proteins, gels, colours and vitamins, This thinks that it should be possible to create an appealing array of foods. The list of possible ingredients is long, including, for example, 1-octen-3-ol, with its scent of wild mushrooms, limonene, and tyrosine, an odourless but flavour-packed amino acid found in cheese. Then there’s methional, responsible for the unmistakeable earthy smell that hits you when you boil potatoes, and myriad others. This envisages that the note-by-note food could be as nutrient-packed as required, simply by adding ingredients such as proteins and vitamins.
This is keen to spread the word about note-by-note cooking and is also working on encouraging flavour producers to sell chemicals directly to the public, rather than just to industry. One of note-by-note’s selling points, he says, is that of significant energy and cost savings through cutting transport. He takes the examples of fresh tomatoes, laden with water. Instead of transporting the fresh product, the valuable chemicals locked in the fruit could be extracted in situ, he suggests. The water could then be added back when the tomatoes are needed. Farmers will benefit, he suggests, in the same way as they do when producing cheese from milk or wine from grapes.
Meanwhile, a student team on a Masters course in food innovation and product design – run jointly by AgroParisTech; the University of Naples in Italy; Lund University, Sweden; and Dublin Institute of Technology in Ireland – suggests that freeze-drying could play a part in fighting food poverty, by reducing food waste.
The students were recently named runners-up in an industry-sponsored Thought for Food (TFF) Challenge for their ‘FoPo food powder’ project. They were ‘pipped to the post’ by a solar-powered chamber for small-scale farmers that increases the shelf life of fruit and vegetables using evaporation cooling.
TFF sets the hefty task of developing ‘breakthrough projects that address the global challenge of feeding nine billion people by 2050’. The FoPo idea is to freeze-dry ‘ugly, unsellable’ fresh produce nearing its expiry date to convert it into a ‘nutritious powder that can be used for humanitarian aid, space missions and more’.
The FoPo team is not adapting freeze-drying technology, merely giving it a different application. ‘In theory, it is possible to freeze-dry anything containing water,’ says team member Vita Jarolimkova. Although it is cheaper to preserve fruits and vegetables using other drying technologies, ‘the nutritional content is negatively affected and water removal is often only partial, leading to shorter shelf-life,’ she explains. Other similar technologies may have lower processing costs, but the capital cost is many times higher and would not pay off for small-scale production, adds Jarolimkova.
‘If we aim to preserve nutritional content at around 95%, prolong shelf-life to two years and longer, and remove almost all water, freeze-drying is the best alternative, given the price: quality ratio,’ she says. The main challenge remains to find a way to cut the cost of freeze-drying. The FoPo team is currently running pilot tests in The Philippines. Not only are levels of food waste high there but the country also has a history of major environmental catastrophes, leading to increased food insecurity and limited supply of fruits and vegetables to the victims, adds Jarolimkova.
‘We are at a real pivot point in our history as a society,’ says culinary scientist Ali Bouzari. ‘We are coming up to very real challenges – from how long are we going to be able to eat the way we are eating, to how do we manage waste streams.’ In 2014, Bouzari got together with two chef friends to found US-based Pilot R&D, a consultancy and food ‘think tank’ that aims to find solutions to ‘culinary obstacles’ identified by restaurants and industry.
Bouzari is fired up by the challenge of how to make good use of food waste. He uses carrot juice as an example. ‘All of the pulp that is left over is traditionally composted but there are things that can be done with carrot pulp,’ he says. Bringing together a chef’s imagination, a ‘restaurant ideology of waste nothing’ and scientific knowledge can give rise to ‘all sorts of interesting possibilities’, from pectin-based desserts to fermented relishes, he suggests. ‘We go into a kitchen with a chef’s set of tools and a scientist’s methodology and knowledge – with that, we can address 90% of problems,’ he says.
The only ‘lab kit’ that Bouzari and his colleagues require is a ‘really good thermometer and a pH meter’. His approach, he says, is more analytical rather than preparative. ‘Centrifuges, rotary evaporators and homogenisers are great but where you bring about the most change is in giving a risotto chef insight into how lipids and starch and water co-mingle. That’s what we’re excited about.’
‘I wish we could have had chef–scientist hybrids in the days of the industrial food revolution. We have this really weird regime where sterilisation is the only method of preservation,’ adds Bouzari, pointing to unappetising products such as canned spinach. ‘If there had been a chef in that conversation, the idea would have been scrapped,’ he jokes.
Bouzari is particularly scathing about bottled lemon juice. ‘I would much rather use a quality vinegar or just a lemon,’ he says, also recommending Moroccan style preserved lemon, packed with salt, herbs and spices. He and his colleagues have a particular interest in microbes, especially for preservation. ‘For example, there’s a lot of really interesting microbiology going on in preserved lemons,’ says Bouzari. ‘What happens over ageing of preserved lemon is you get enzyme activity that breaks down the cellular structure of the lemons to form a paste,’ he explains. Beneficial lactic acid bacteria prevent growth of pathogens, which could harm the flavour. ‘You get this softening of flavour, fantastic aroma production and shelf stability without having to sterilise because you have got low pH, low water activity and such an abundant microbiota,’ he says.
Svetlana Rodgers, director of the Australian Food Service Academy, has a particular interest in lactic acid bacteria, commonly isolated from cheese and fermented vegetables. During her research days at the University of Brighton, UK, she demonstrated that lactic acid bacteria can prevent growth of Clostridium botulinum. In her current role, she is keen to help companies ‘take full advantage of natural microflora in food protection and health – to replace chemicals with protective cultures’.
Such protective cultures are not widely used in the catering sector, she says, possibly because of a ‘low level of technical competencies’. Yet microbes have always been used for fermentation, with microbial ‘terroir’ all the rage in selected restaurants such as Momofuku in New York, US. Fermentation obsessions can be taken too far, jokes Bouzari. He recalls a chef at a ‘very fine dining restaurant’ trying to make beer from scallops, because of their high sugar content. The fermentation worked but it tasted ‘really terrible’.
However, Bouzari is all for such experimentation. ‘There’s no harm in taking a look as long as you don’t become married to an idea.’ He concludes: ‘The power of critical thinking is the new secret ingredient.’
Emma Davies is a science writer based in Bishop’s Stortford, UK