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How the scientific discipline of molecular gastronomy could change the way we eat Hervé This

or years, a new culinary trend called does not concern food fashions or how to century BC by Apicius (André (ed), 1987), ‘molecular cooking’ has been touted prepare luxury food—such as tournedos and recipes for stock preparation appear in Fas the most exciting development in Rossini, canard à l’orange or lobster orien- classic texts (La Varenne, 1651; Menon, haute cuisine. It is now the newest fashion tale—but rather an understanding of food; 1756; Carême & Plumerey, 1981) and most for chefs to offer their customers fake caviar and for the more restricted ‘molecular gas- French culinary books. made from sodium alginate and calcium, tronomy’, it is the chemistry and physics burning sherbets, spaghetti made from veg- behind the preparation of any dish: for …there is a difference between etables, and instant ice cream, fast-frozen example, why a mayonnaise becomes firm using liquid nitrogen. In the most recent or why a soufflé swells. the science of ingredients and the ranking of the world’s top 50 chefs—by the Of course, the ‘molecular’ in molecular science of culinary processes British magazine Restaurant—the top three gastronomy has the same definition as it chefs were Ferran Adria from El Bulli in does in molecular biology. The similarity is Rosas, Spain; Heston Blumenthal from The intentional, because chemistry and physics Chemists have been interested in meat Fat Duck in Bray, UK; and Pierre Gagnaire are at the core of this discipline, and I will stock preparation and, more generally, food from his restaurant in Paris, France return to this point to explain how physics preparation since the eighteenth century (Restaurant, 2006). In 2005, Blumenthal and chemistry can change cooking. But it is (Lémery, 1705; Geoffroy le Cadet, 1733; was first and Adria came second. What is clear that molecular gastronomy is a new Cadet de Vaux, 1818; Darcet, 1830). remarkable is that all three of these talented science, and that there is already much Antoine-Laurent de Lavoisier is perhaps the and popular chefs have been inspired by more to it than what we read in the press. It most famous among them—in 1783, he molecular gastronomy. is quite possible that a European Molecular studied the processes of stock preparation Gastronomy Organization will one day be by measuring density to evaluate quality …the science of food is not new created; there are already such organiza- (Lavoisier, 1783). In reporting the results tions in many countries, such as Argentina, of his experiments, Lavoisier wrote, Switzerland and Spain. Molecular gastron- “Whenever one considers the most familiar What is molecular gastronomy? Is it only a omy has developed the furthest in France, objects, the simplest things, it’s impossible temporary trend for people who are prepared where the Fondation Science & Culture not to be surprised to see how our ideas are to spend a small fortune on the latest in fine Alimentaire (Foundation ‘Food Science & vague and uncertain, and how, as a conse- food, or is it here to stay? Is it a useful tech- Culture’) has been created this year by the quence, it is important to fix them by experi- nique for both the average chef and anyone French Academy of Sciences. ments and facts” (author’s translation). Of preparing dinner for their family? What does Before telling the story of molecular and course, Justus von Liebig should not be for- it mean for the future of food preparation? physical gastronomy—which later became gotten in the history of culinary science (von What are we going to eat tomorrow? molecular gastronomy—I want to empha- Liebig, 1852) and stock was not his only size that the science of food is not new. In concern. Another important figure was irst, I will define molecular gastronomy, the second century BC, the anonymous Benjamin Thompson, later knighted Count because there is still much confusion in author of a papyrus kept in London used a Rumford, who studied culinary transforma- Fthe media about the true meaning of balance to determine whether fermented tions and made many proposals and inven- this term, in part because of mistakes meat was lighter than fresh meat. Since tions to improve them, for example by Nicholas Kurti and I made when we created then, many scientists have been interested inventing a special coffee pot for better the discipline in 1988. But I will start by dis- in food and cooking. In particular, the brewing (Kurti, 1995). tinguish between cooking and gastronomy: preparation of meat stock—the aqueous There are too many scientists who have the first is the preparation of food, whereas solution obtained by thermal processing of contributed to the science of food prepara- the latter is the knowledge of whatever con- animal tissues in water—has been of great tion to list here; however, there is a differ- cerns man’s nourishment. In essence, this interest. It was first mentioned in the fourth ence between the science of ingredients

and the science of culinary processes. In laboratory at the Collège de France, and in the 1980s, food science was engaged 1996, I presented the first PhD in mainly in analysing the contents and prop- ‘Molecular and Physical Gastronomy’ at erties of food, and how they relate to the the University of Paris (This, 1996). When demands of our bodies, and in developing Kurti died in 1998, I shortened ‘molecular methods to process food on an industrial and physical gastronomy’ to ‘molecular scale. However, millions of people who gastronomy’—as it should have been from prepared food for themselves or their families the beginning—and added Kurti’s name to had no science to help them understand the title of our international workshops. what they were doing. ecipes, the most important written espite having a huge impact on form of culinary knowledge, tradi- other aspects of our lives, scientific Rtionally consist of two parts. The first Dadvances have done little to is a ‘definition’: for example, a soufflé is a change our cooking habits. When it comes foamy product that swells during cooking, to preparing food—the most important and crumples once someone pokes a knife aspect of our life from a physiological point or fork into it (otherwise it would be a of view—citizens in developed countries cake); or a mayonnaise is an emulsion of still cook almost the same way as their oil in egg yolk, salt, pepper and vinegar. In ancestors did centuries ago. Of course, general, these definitions are usually some foods and products—notably pota- mixed with ‘materials and methods’ in the toes, tomatoes and new spices—were form of a cooking protocol: how many to introduced into European cuisines only use of each ingredient for a given number after the discovery of the New World and of guests and how to process, blend and with increasing trade with Africa and Asia, cook these ingredients to turn them into but the culinary processes themselves did the final product. In addition, a recipe not change. Kitchens are equipped with might contain what I call ‘culinary preci- basically the same pans, whisks and sieves sions’, such as hints and advice, old wives’ that cooks used in the seventeenth century. tales, tricks, adages and maxims. Similarly, culinary books from the four- Take, for example, an eighteenth century teenth century to the twenty-first century book that advises us to cover the pan when all look the same, despite the introduction beef is cooked with water to produce stock of new recipes; for example, the first emul- (Albert, 1838). If this recommendation is sion described in a French culinary book correct, why? And if it is not, why did some- appears in 1674 (LSR, 1674), and the one write this sentence more than 150 years ancestor of mayonnaise seems to be a ago? To answer this question, we can use beurre de Provence (Marin, 1742). tools from physics, chemistry and biology— Indeed, cooking was the last of the for example, the microscope, the thermo- ‘chemical arts’ to become the object of meter and the gas chromatograph—to inves- scientific scrutiny and it still relies on tell- tigate the processes that take place during tale and anecdotal knowledge rather than cooking. If we can answer the question, we solid science. As recently as 2001, an can correct a mistake, use this knowledge to inspector from the French Department of improve the cooking process or even invent Public Education said, during a public lec- new scientific discipline to investigate new dishes or ways to prepare food. ture, that her mayonnaise failed when she culinary transformations. One example of how chemistry and was menstruating. Such old wives’ tales First, we had to find a name and a scien- physics can lead to new ways of cooking is were partly the reason behind the creation tific programme to state the goals of this provided by the egg. If we heat an egg, of molecular gastronomy: I first started new discipline. Consequently, we orga- water evaporates, the proteins denature experimental studies of cooking after nized the International Workshop on and polymerize to enclose water, and the encountering a recipe for cheese soufflé Molecular and Physical Gastronomy in end result is a cooked egg. Is there another that advised adding egg yolks “two by two, 1992, held at the Ettore Majorana Centre way to do this? Yes, alcohol can do the never by fractions”. Another reason was for Scientific Culture in Erice, Italy, and same trick because it can denature pro- that the late Nicholas Kurti, professor of invited chefs and scientists from all over the teins; thus we achieve the same result by physics at Oxford University, UK, was world. The success of this first meeting led adding liquor to a raw egg. Similarly, the upset by the poor and unscientific way us to repeat it every two years. In 1995, scientifically proven way to obtain an airy that people cook (This, 1999). Initially, a Jean-Marie Lehn, who won the 1987 Nobel soufflé is to heat it from below, so the evap- handful of other people conducted separate Prize in Chemistry with Donald Cram and orating water pushes the dough upwards. studies of culinary processes, but in 1988, Charles Pedersen, invited me to create the This is simple physics but it can help us to Kurti and I decided that we should create a first Group of Molecular Gastronomy in his make better food.

nitially, as written in my PhD disserta- molecular gastronomy. Universities in various tion, molecular gastronomy had five NEW DISHES NAMED AFTER countries, such as the Netherlands, Denmark Iaims: to collect and investigate old FAMOUS CHEMISTS and Argentina have set up professorships in wives’ tales about cooking; to model and Since 2005, new dishes, produced on the basis this discipline. scrutinize existing recipes; to introduce of the results of molecular gastronomy, have Despite this spread of knowledge and new tools, products and methods to cook- been named after famous chemists or interest, mistakes are still made. In 2002, ing; to invent new dishes using knowledge scientists, so people are now eating ‘chemistry’. for example, the media described some from the previous three aims; and to use This is one way to fight the public’s fear of chefs as ‘molecular gastronomists’, which is the appeal of food to promote science science and to promote the diffusion of obviously wrong because chefs create food, (This, 1995). Today, it is easy to see that this knowledge. not knowledge. This confusion was caused scientific programme was misleading and in part by our scientific programme, which Gibbs had shortcomings, and it is surprising that When an egg white is whipped with oil, a white was not purely scientific but included tech- no member of the PhD panel—including emulsion is obtained. If this emulsion is nological applications and education. From two Nobel laureates—mentioned it. The first cooked in a microwave oven, water heats and the beginning, Kurti and I agreed that mol- two aims are really scientific goals, the third expands. At that time, the temperature is about ecular gastronomy was science and not and the fourth are only technological appli- 100°C, which is higher than the coagulation technology, so we excluded the technological cations, and the fifth aim is an educational temperature of egg-white proteins. The and educational elements. application of the first four. emulsion is then trapped into a gel. Of course, Accordingly, our scientific programme oil does not necessarily taste good, but imagine became clearer when we reduced it to two infusing vanilla pods in egg white, dissolving aims: to model definitions, and to collect sugar into the mixture and adding very good Despite having a huge impact on and scrutinize culinary precisions. However, other aspects of our lives, scientific olive oil before microwave cooking. The product is called a Gibbs, after the famous we rapidly found this new programme insuf- advances have done little to physicist Josiah Willard Gibbs (1839–1903). ficient as well, because the main aim in change our cooking habits cooking is to produce good food, which is Vauquelin art and not technique. Furthermore, a dish When an egg white is whipped, a small can be cooked perfectly, but if it is not pre- Nevertheless, the programme attracted quantity of foam is formed: about 300 ml for sented in an appealing way, all the art and a lot of media coverage, not least for the one egg white. Why not more? As whipped egg science will mean little to the customer or chefs who collaborated with us to develop white consists primarily of water (around guest; we therefore decided that we must molecular gastronomy. In France, the field 90%), proteins and air, it is easy to discover include the ‘love’ component of culinary that adding water will produce more foam. If advanced and spread through monthly practice. Of course, science will probably the foam is cooked in a microwave oven, a seminars, national congresses, courses on chemically jellified foam is formed. To achieve never be able to fully explain art or love, but molecular gastronomy and the creation of a better-tasting product, use orange juice or it can help; for example, evolutionary biolo- the Foundation ‘Food Science & Culture’ cranberry juice instead of water, and add sugar gy can contribute to the exploration of (This, 2006). Among the chefs who make to increase the viscosity and to stabilize the human behaviours, and, accordingly, culi- use of molecular gastronomy, many are foam before cooking. This new dish is named nary practice. Consequently, molecular famous: for example Christian and after Nicolas Vauquelin (1763–1829),one of gastronomy not only uses science to explore Philippe Conticini, Bernard Leprince, Lavoisier’s teachers. the technical aspect of cooking but also the Michel Roth and Pierre Hermé, all from ‘art’ and ‘love’ components, both of which Paris; Ferran Adria from Rosas; Michel Bras Baumé are important for the main aim of cooking: to Have you ever put a whole egg into alcohol? If from Laguiole; Pierre Gagnaire, who has delight guests. you are patient enough, ethanol will permeate restaurants in Paris, London, Tokyo and the shell and promote coagulation. After about Hong Kong; Heston Blumenthal in Bray; one month, the result is a strange coagulated et me try to explain the art component and Emile Jung in Strasbourg. Between egg called a Baumé, after the French chemist of cooking scientifically. In 2002, I 2002 and 2005, a European technology Antoine Baumé (1728–1804). Lintroduced a formalism to describe, in transfer programme—Inicon—promoted a non-periodical manner, the organization collaboration between European chefs, of food space or different foodstuffs. All scientists, companies and culinary ducational efforts are equally impor- foods are complex disperse systems, also schools. One very important event was a tant. In 2001, the Ateliers called ‘soft matter’. The simplest of these ‘science and cooking’ menu served by EExpérimentaux du Goût (experimental systems—formerly called colloidal—are Pierre Gagnaire at the Academy of workshops on flavour) were created in well known: emulsions, foams, gels and so Sciences, during a lecture on molecular French schools. Since then, Canada and forth. However, when food involves more gastronomy at the beginning of 2000. France have introduced new curricula for than two phases, this classical description The creation of an online presence culinary schools to include knowledge is no longer sufficient to describe something (www.pierre-gagnaire.com), which lists a obtained from molecular gastronomy. In as simple as custard—which is probably new application of molecular gastronomy 2005, the Institute for Advanced Studies why physicists eventually gave up trying to every month, has also contributed to the rapid on Flavour, Gastronomy and the Culinary find a global description of complex sys- spread of this discipline among scientists Arts was created in Reims, France, to pro- tems and instead focused on interfaces and chefs alike. mote gastronomy knowledge, including between different phases (Israelachvili,

1992). But food needs more than interfaces mayonnaise, crunchy crackers. This is why developments will inevitably have an impor- to describe it; even a simple sauce such as consistency is an important factor of all food, tant impact on what and how we eat and, a béarnaise consists of three phases: solid and why cooks care so much about it. accordingly, on how we prepare our food. matter (microscopic egg-yolk aggregate) I therefore proposed an additional for- and a hydrophobic liquid (oil droplets) dis- malism, which I first introduced in 2004 to persed in a hydrophilic liquid (water). In describe the organization of foodstuffs Cooking has to be explored order to describe the microscopic structure (This, 2005). It includes the ‘consistency’ of scientifically if we want to of such a system, we proposed the ’com- food by describing its firmness: gas is attrib- improve educational health plex disperse systems’ (CDS) formalism in uted a firmness level of zero; a liquid, one; programmes 2002 at the European Colloid and Interface an emulsion, two; a jellified emulsion, Society Meeting (This, 2003). three; and so forth up to infinity, for example to describe chewing gum. Using this Together, these developments further …cooking was the last of the scale, what food has level four or five, for strengthen the idea that children must get example? This is why understanding food more information about food and food ‘chemical arts’ to become the needed some formalism to describe food preparation. Decades of research on nutri- object of scientific scrutiny and preparations in terms of consistency. On the tion now provide us with a large amount it still relies on telltale and basis of this formalism, we can perform the of data on what and how much our bodies anecdotal knowledge rather than same research as for sauces using the CDS need to stay healthy, but the current trend solid science formalism and, in this way, study the art towards obesity is in good part caused by a component of food. This is interesting not fatal attraction to junk food, soft drinks only from a purely scientific point of view: and sweets. Consequently, health pro- So what is the scientific usefulness of this if we are able to understand why a certain grammes that promote a balanced diet formalism? I applied it to all classical sauces food is tasty and pleasurable, we can cannot succeed if people are unable to in French culinary history, from sauce describe its preparation scientifically so make intelligent choices about food. africaine to sauce zingara, and showed that even inexperienced cooks are able to make However, traditional cooking is not a guar- their number has increased regularly since a good dinner without having to rely on antee either for healthy food or for a rational the fourteenth century; in 2005, French cui- years of experience or old wives’ tales. preparation of food. sine had developed 23 different systems This is where the scientific programme (This, 2004): solutions, oil-in-water emul- o what is the future of food once we of molecular gastronomy can be useful. If sions, foamed emulsions, and so forth. Now, start to explore it scientifically? The dif- we are able to use the knowledge gained using the CDS formalism, the number of dif- Sficult thing about the future is that it is on food preparation, we might find new ferent sauces is potentially infinite, because hard to predict. We should avoid making the ways to make healthy food more attractive, new formulas can lead to new sauces and, same mistakes that French chemist Marcellin we might persuade more people to cook more generally, to new dishes. Berthelot made about a century ago: he pre- better food and, last but not least, we might Similar to the study of how sauces have dicted that the success of organic chemistry convince society to regard eating as a plea- evolved over time, we can also study how would allow us to abandon traditional food sure rather than a necessity. I have now these sauces evolved aesthetically—indeed, and, by the year 2000, eat nutritive tablets collected more than 25,000 culinary preci- in 2004, it became obvious that if we want to instead (Berthelot, 1894). He was obviously sions, but they still need to be scrutinized; study the art component of culinary practice, wrong—humans are living organisms, with without more knowledge, culinary books we have to analyse the aesthetics of food. an extremely sophisticated sensory appara- cannot be regarded as reliable. Moreover, The great German writer and philosopher tus that has evolved over millions of years to educational programmes cannot rely only on Johann Wolfgang von Goethe wrote to the detect odour, taste, consistency, temperature traditional recipes, because products, meth- German writer Friedrich Schiller: “One and more. The pleasure of eating involves all ods and ingredients have changed over essential characteristic of epic poetry is that our senses and it is obviously important for time. Cooking has to be explored scientifi- it goes forth and back constantly, hence the our wellbeing—why else did our ancestors cally if we want to improve educational epic character of all delaying motives” start to cook their meat and vegetables even health programmes. (Goethe, 1797). Similarly, food can be before they invented civilization? And what does molecular gastronomy explained as a story, with a beginning—the One of the most important and worrying hold for chefs? For them, the scientific explo- ingredients are organized into a dish—and trends is the current pandemic of obesity. ration of cooking is even more important. an end: when the plates are empty and the Even in Crete, where the so-called ‘Cretan Science is the basis for technology and new guests satisfied. But the story would be a diet’ originated, up to one-third of 12-year- innovations, so this field will help them to short and boring one if food were just a liq- old children are now overweight or obese create exciting new dishes and inventions. uid, because our brains are built to detect (IOTF, 2003). Another clear trend is the All sciences are useful for this enterprise, not contrasts and draw pleasure from them. Of increasing concern for our environment and only chemistry and physics, but also biology, course, food is mostly water, but this water is healthy food, and the increasing proportion as well as history and sociology. However, organized—for example, in the cells of plant of humans who live in cities. Finally, there is for chefs, and hopefully for non-chefs as and animal tissues—and proper preparation a growing divide between scientists and well, the main aim is to surprise and delight brings about the contrasts and the consistency laypeople, and an increasing disaffection in their guests or their family with exciting, of different foodstuffs: tender meat, firm society for science and research. All these tasty and healthy food.

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