Why Limit Ourselves to Silverware?

THURSDAY, 20 SEPTEMBER 2018

With every spoonful of food you eat, you are  also consuming billions of atoms worth of the spoon's material. It should therefore come as no surprise that your spoon’s composition affects the taste of your meal. Dr Mark Miodownik, Professor of Materials and Society as well as director of the Institute of Making at University College London, has been exploring this very topic for several years now.

In a 2012 study published in the journal of Food Quality and Preference, Miodownik and collaborators presented the first study which aimed to establish a relationship between the perceived pleasantness of food and the composition of the cutlery used to consume it. The food samples, which were tasted by a group of thirty volunteers, consisted of five double cream samples which had different tastes: sweet (table sugar), sour (lemon juice), bitter (lemon pith), salty (table salt) and plain. The samples were tasted using four stainless steel spoons, three of which were electroplated with either zinc, copper or gold. The study concluded that different metals taste different, and, additionally, can strongly influence how food tastes. A particularly interesting finding was that zinc and copper spoons enhanced each cream sample’s dominant taste. Even more surprising is that although zinc- and copper-plated spoons have an unpleasant metallic taste, they did not significantly affect the perceived pleasantness of the cream samples. Based on this finding, the authors suggest zinc or copper cutlery could be used for special diets which require low salt or sugar intake, for example.

Another proposed application for the difference in taste offered by different spoons was the creation of cutlery and food pairings, much like food and wine pairings, to create interesting culinary experiences. The food and cutlery pairing experiment was carried out by Miodownik’s team by hosting a meal at Michelin-starred Indian restaurant Quilon in London in the company of a varied group of guests including chefs, food writers, and scientists. Attendees were presented with a seven course menu alongside seven spoons coated with different metals. Gold was chosen as the overall best spoon, as it offers “a smooth, almost creamy quality, and a quality of absence – because it doesn’t taste metallic” explained Dr Zoe Laughlin to the Financial Times. Both artist and scientist, Laughlin is the co-director of the Institute of Making and orchestrated the original spoon tasting experiment. For those of us unable to invest in gold cutlery, tin proved to be a surprise hit, and provided a particularly good match for pistachio curry. Other pairings proved less popular, as explained by cook and food writer Fuschia Dunlop in an article for the Financial Times: “Baked black cod with zinc was as unpleasant as a fingernail scraped down a blackboard”.

The spoon experiment forms part of a greater area of materials science research pioneered by Miodownik called 'sensoaesthetics', which aims to relate scientifically the physical properties of materials to a person's sensory response to them through sight, sound, touch, smell and taste. Such matters have always been of prime concern to designers and architects, but have rarely been explored by scientists. For example, some materials are considered cold (e.g. metals) while others are considered warm (e.g. wood), and this plays a role in how they are used in interior design. In reality, this has nothing to do with the absolute temperature of the material; the correlation of perceived temperature with material type relates to the material’s rate of heat transfer. Metals are excellent thermal conductors, so upon touching them, they efficiently draw heat away, which gives the impression that they are cold. Wood, on the other hand, is a thermal insulator, which is why it feels warmer to the touch.

A better understanding of the link between a material's physical properties and the response it elicits from touch, taste, smell, or sight can provide new opportunities for material design which incorporates the information arising from our different senses, also known as multisensory integration. One application for sensoaesthetic optimisation is the smell, feel, and appearance of hospital wound dressings. There is a mounting body of evidence showing that a patient’s perception of their healing process, including the aesthetics of their wound dressings, is correlated with faster patient recovery rates, which in turn contribute to reducing the cost of operation of hospitals.

In addition to carrying out fascinating research, Professor Miodownik is committed to improving public awareness and understanding of materials science.  His book "Stuff Matters" presents the science behind everyday materials and objects, from porcelain teacups, through elasticised underpants, all the way to towering skyscrapers. The book was a New York Times bestseller and received the 2014 Royal Society Winton Prize for science books. He is the most recent recipient of the prestigious Royal Society's Michael Faraday Prize and Lecture, awarded annually to scientists and engineers such as Sir David Attenborough and Brian Cox for excellence in communicating science to UK audiences. He also engages in radio and television interviews and feature both as a participant and a producer. Last year, Miodownik produced a BBC Four program entitled “Chef vs Science: The Ultimate Kitchen Challenge” in which he competes against a Michelin-starred chef to craft a delicious meal using his knowledge of science and access to state-of-the-art technology. Spoiler alert: there is a reason why Michelin-starred chefs achieve celebrity status in the culinary world.

Since 2013, Miodownik and his collaborators have been introducing sensoaesthetics to the public via the Institute of Making’s Materials Library at University College London. The library contains over 1500 unusual and unique materials including freeze-dried ice cream, self-healing concrete, and ferrofluid, a magnetic liquid developed by NASA. The library is accompanied by a Makespace which allows members of the general public to interact with the materials on special open days. Allowing non-scientists to play with different materials offers a direct mechanism to study the interplay of one’s senses and the material’s physical properties.

Two years ago, Miodownik published a piece in which he predicts technological advances and their impacts on mankind for the next 50 years. Alongside his musings on the future of sustainable cities, energy, food, and healthcare, he also emphasises the importance for materials scientists to work in close collaboration with designers, architects, and artists, the so-called “materials artists”. Sensoaesthetics is a burgeoning research area, so we can expect important developments in the understanding of mankind’s sensual and emotional connection to materials. In the words of Professor Miodownik, “Whatever happens, it seems certain that humanity’s love affair with stuff is not going to end any time soon. Materials are, quite literally, a physical reflection of who we are, and as long as we are changing, so will our material world.”

Bianca Provost is a 4th year PhD student in the Department of Chemistry at Girton College, Twitter: @biancaprov. Artwork by Sean O'Brien