Readers well aquianted with the food blogosphere will likely be familiar with Aki Kamozawa and Alex Talbot’s blog Ideas in food. Since December 2004 they have generously shared pictures, ideas, insights and inspirations online. As chefs they have eagerly integrated modernist techniques and elements in their cooking, allowing technology to improve their cooking whenever possible. No wonder I’ve been a long time follower of their blog! And needless to say I was also exicted to receive a review copy of their recent book Ideas in food: Great recipes and why they work.

First and foremost the book is a great collection of ideas explored by the authors. The ideas are exemplified through recipes (about 100 in total) which showcase the creativity of the authors, from the simple vanilla salt to innovative pasta and risotto techniques, red cabbage kimchi with a built in pH indicator, grilled potato ice cream and practical examples of how hydrocolloids can be utilized. It is certainly an engaging book, and my copy is filled with countless comments, “Try this!”, “Interesting!” and enthusiastic exlamations, but also question marks and disagreement. For some reason the book has been divied into Ideas for everyone and Ideas for professionals, the latter dealing mainly with hydrocolloids. But why the discussion of starch and gelation is reserved for the professionals whereas the recipe for homemade mozarella which calls for lipase, citric acid and rennet is placed in the “for everyone” section, eludes me.

I suggest you have a pencil ready when reading the book!

As the title suggests there are not only ideas and recipes, but also exlanations that sometimes dig deep into food science. The real strength of the book are the cases where a deeper understanding of the underlying science leads to new ideas. Having explored potatoes and hydration of starch, a simple yet brilliant idea which comes out of this is the parcooked rice (65 °C for 30 min) which subsequentially allows for a superfast risotto. As elegant is the hydration of dried pasta by soaking in cold water. Once hydrated, the pasta is drained and kept in a closed container/bag in the fridge. When dropped into boiling water the pasta will cook as fast as fresh pasta. Combining this with other ideas led to a mac’n cheese made from roasted pasta that is smoked and then hydrated in milk, reserving the excess milk with the surface starch for later stage to help thicken the sauce.

Pasta hydrates in cold water (1:4 ratio of pasta to water) within a couple of hours. The fully hydrated pasta cooks within a couple of minutes.

Explaining the science of food and cooking in lay terms is difficult, especially when striving for simple and correct explanations. On some occasions the authors strike a good balance here, but at times the explanations are either too simplistic or too detailed to be of any real help. I was often left with a feeling that the text desperately called for illustrations for the reader to properly grasp the concepts, for instance in their discussion of amylopectin, amylose and starch granules. Perhaps it’s because I’m used to science text books, but the fact that Ideas in food doesn’t have a single figure, diagram or photo is a drawback in my opnion.

Understanding how amylose and amylpection would be easier had they included a simple drawing like this one.

Ever since reading Hervé This’ book Révélations gastronomiques (available in German as Kulinarische Geheimnisse, not available in English) I have appreciated the approach that combines recipes with answers to the many whys that pop up in my mind. Comparing Ideas in food: Great recipes and why they work with This’ book, what shines through at places is the author’s lack of scientific training. Without doubt they know much more food science than the average chef, but it is surprising for instance that the Maillard reaction is not mentioned in their discussion of stocks. And the precision of the recipes is often questionable, especially regarding their use of metric units in the first section. Saying that 1/2 cup of milk equals 130 grams makes sense to me because I expect to see a rounded number. But an online conversion calculator I often use says that for milk 0.5 US cups = 121.8 g = 118.3 ml, so I would naturally have rounded this to 120 grams. On the other hand, when the authors state that 8 3/4 cups of water equals 1968.75 grams the precision implied by the number of digits will make for a good laugh for scientists reading this. And I’m puzzled by how the “cups” used apparantly range from 225 to 260 mL – is there something I’m missing here?. The ultimate solution to this of course would be to eliminate the United States customary units alltogether (sorry all Americans!). Ironically this is exactly what the authors did in the “Ideas for professionals” section.

In the light of the recent paper on the 6X °C egg the whole chapter on “perfect” eggs seems a little outdated. The recipes are probably fine (I haven’t tested them), but I was surprised to read that egg whites coagulate from 60-65.5 °C (this must be a typo) whereas egg yolks coagulate from 65-70 °C (true, but they start to coagulate at a lower temperature, and it’s a function of time and temperature).

To conclude, the compilation of great food ideas is what I found most rewarding in the book. And despite the shortcomings mentioned above I would wholeheartedly recommend the book, simply because of all the nice examples of how a new technique or theoretical insight can be extrapolated into related areas and lead to new ideas in the kitchen. I suggest that you get Ideas in food: Great recipes and why they work for it’s collection of ideas and the creativity of the chefs. But if you’re interested in the whys of cooking you will be better served by other books, the obvious choices being On food and cooking and Keys to good cooking by Harold McGee or The science of cooking by Peter Barham.

Ideas in food – Great recipes and why they work
Aki Kamozawa and Alexander Talbot
320 p, no illustrations/photos
2010, Clarkson Potter
ISBN 978-0-307-71740-5

In case you didn’t know the current world record for the world’s fastest ice cream is 10.34 seconds! To obtain the record you have to make one liter of ice cream from milk, sugar and flavoring (no eggs). Liquid nitrogen is used to rapidly cool and freeze the ice cream mixture. The current record was achieved by Andrew Ross (UK) at Cliffe Cottage in Sheffield,​ South Yorkshire,​ UK, on 6 June 2010. Prior to that the world record belonged to Peter Barham who in 2005 shaved two seconds of his previous record, ending at 18.78 seconds. To conclude his presentation on how food can be used to make students interested in physics and chemistry Peter decided to beat the current world record. Here’s a video of how it went:

Want to read more about the history of liquid nitrogen ice cream and find recipes? Then you should visit the webpages of The institute for liquid nitrogen ice cream experimental studies!

Peter Barham’s presentation at the MG seminar in Copenhagen focused on how food can be used to make students interested in physics and chemistry (not a bad thing, especially since 2011 is the International Year of Chemistry) -Most people think science is boring and difficult, he said. But demos can help bring science to life, and believe it or not – experiments are much better when they go wrong. Using balloons, champagne, potatoes and liquid nitrogen Peter Barham proved his point. As an example he asked the audience how much air weighs. He first filled a balloon with a few milliliters of water, then squeezed out all the air, tied a knot and heated the water in the microwave until all had evaporated. The first balloon exploded since he used to much water (this shows that water expands when boiled and that balloons are not infinitely stretchable!). Using a little less water for the second balloon, everything worked fine. Assuming that steam has approximately the same density as air, the size of the balloon can be measured and from this the weight of air be calculated. One finds that the volume of the water increases by a factor of approximately 800x.

There will be more foam when champagne is poured into a dirty glass due to more nucleation sites providing the dissolved carbon dioxide with more escape routes.

Ever heard about how a spoon in the neck of an opened champagne bottle can keep the champagne fizzy? Well unfortunately this is a kitchen myth. The only thing that helps is keeping the bottle cold. The spoon has no effect whatsoever. And the balloon once cooled can help illustrate this. When all the steam had condensed there was a significant amount of gas left in the balloon (remember that all the air was squeezed out to start with). This illustrates that gases are soluble in water at low temperature, but not at higher temperature. When water is boiled the gas escapes. Gas (and in particular carbon dioxide) is more soluble at lower temperatures, and that is the explanation why champagne may retain quite a lot of the fizz if stored cold. The spoon is only there to confuse you!

How long does it take to boil a potato?

Next question was: How long does it take to boil potatoes? Since the visual appearance of a potato changes around 60 °C it is possible to monitor heat transfer by simply slicing a potato in two. If boiled in water a nice ring with a slightly darker color indicates how the heat travels uniformely towards the center. If you plot the width of the ring against the square root of the time you get a nice straigth line. However, if heated in a microwave a different pattern emerges. The wavelength of microwaves is on the order of several centimeters and as a consequence the distance between hot and cold areas are about 2 cm. Slicing a microwaved potato shows how only one side has been heated. This is the simple reason why food heated in a microwave oven must be left to stand for a while to allow the heat to diffuse.

When heated in boiling water the heat travels uniformly towards the center of the potato as evidenced by the “ring” that occurs once the temperature reaches 60 °C.

When heated in a microwave there will be hot and cold areas as illustrated with this potato.

Peter Barham also mentioned the experiment that demonstrates the difference between taste and aroma. If you close your eyes, hold your nose and have a friend give you either a piece of apple or pear, you’ll have a difficult task saying which is which. But the second you let go of your nose you recognize what you have in your mouth. The experiment can also be conducted with lemon and lime or other fruit pairs with similar textures. The reason for this is that when you hold your nose, hardly any air from the mouth will enter your nose through the retronasal passage. As a result you will not be able to “smell” what’s in your mouth. But the second you let go of your nose, air can pass freely and you immediately smell what’s in your mouth. This is also the reason why the aroma of food is subdued if you have a cold and a runny nose.

Close your eyes, hold your nose and experience the difference between taste and smell! Apples and pears taste remarkably similar when the aroma is blocked out by holding your nose.

Peter’s last demonstration was liquid nitrogen ice cream and an attempt to break the current world record of 10.34 seconds. More on that in the next post

According to the journal home page the main areas of interest include:

• Mechanisms of taste and flavour
• How flavour affects liking and satisfaction gained from eating
• Relationships between satiety and perceived quality of foods
• Choice behaviour with respect to food quality and satiety
• Multi-modal integration and multi-sensory perception of flavour
• How all senses play their role in our perception of flavour both in combination and separately
• How ingredients are changed by different cooking methods and in the mouth
• Aroma release mechanisms in the mouth
• Interoception
• The evolution of our organs of taste
• The psychology and neuroscience of food preferences and habit formation

The research project Molecular gastronomy – the scientific study of deliciousness and its physical and chemical basis (Danish homepage) funded by The Danish Research Council was started in 2006. Led by prof. Leif Skibsted people from the Food Chemistry (Jens Risbo, Pia Snitkær Nielsen, Louise Mørch Mortensen) as well as the Sensory Science group (Michael Bom Frøst, Wender Bredie, Per Møller, Line Holler Mielby, Ditte Hartvig) at the Department of Food Science at Copenhagen University have been involved. In addition gastronomic entrepeneur Claus Meyer (noma co-founder) and physics professor Peter Barham (Bristol University) have contributed, as well as the chefs Thorsten Vildgaard (noma/Nordic Food Lab) and Bo Frederiksen (Meyers Madhus). Any of the names sound familiar? They should if you’ve read the recent review published in Chemical Reviews: Molecular Gastronomy: A New Emerging Scientific Discipline where several of the people involved in the project contributed as authors. This landmark paper summarizes and lays out research opportunities in molecular gastronomy, the branch of food science that deals with The art and science of choosing, preparing and eating good food to quote Thorvald Pedersens definition – he is a professor emeritus in chemistry that played an important role helping to establish molecular gastronomy as a research field at the University of Copenhagen.

To mark the end of the project a seminar was organized on March 2nd 2011. The program included the following presentations:

• Reduction of meat stock, what happens? (PhD Pia Snitkjær)
• Flavour pairing (Professor Wender Bredie)
• Chocolate desserts or the importance of phase inversion (PhD student Louise M. Mortensen)
• What’s in a meal? (Associate Professor Michael Bom Frøst)
• Molecular Gastronomy meets the internet (Chemist and food blogger Martin Lersch)
• Molecular Gastronomy – a tool for teaching science (Associate Professor Jens Risbo)
• Food: making science engagement easy (Professor Peter Barham, Bristol University)

As an intermezzo in the program ‘Gastronomisk legestue’ (Gastronomic playroom) presented examples of recent edible works. They are a group of students and young chefs that use the gastronomy teaching lab of the Department of Food Science for gastronomic explorations. I’m very happy I had the opportunity to be present. It  was a very interesting day and I will try to share some impressions with you, so expect blog posts about the seminar and the presentations in the next couple of days. As you can see from the program I was also asked to give a presentation which I will come back to here on the blog in a separate post.

I quote the following from the invitation to the seminar about the purpose of the project:

During the four-year project period we have worked on obtaining a deeper understanding of relationships between products’ physical/chemical characteristics, processes during preparation, and perception of good food. Through experiments in the laboratory, the kitchen, the sensory test room and the restaurant the project has increased the understanding of factors contributing to appreciation of a meal, all the way from choosing the ingredients through preparation to serving and introducing the meal at the dinner table.

An important outcome of the project is the large review of the field: Molecular Gastronomy – a new emerging scientific discipline, which was published in Chemical Reviews in 2010. As a service to the gastronomic society, it can freely be downloaded here.

The goal of the project has been to support inspiration for better foods from gastronomy to science and from science to gastronomy. We strongly believe that working across disciplines, integrating know-how of chefs with the chemical/physical and perceptual/cognitive understanding of food, will contribute to better foods in the future. We believe that our work and future work in this field are important to a positive development of the food sector and our food culture.

I just received an alert today about a major review article on molecular gastronomy: Molecular Gastronomy: A New Emerging Scientific Discipline (DOI: 10.1021/cr900105w) is a British-Danish joint publication by Peter Barham, Leif H. Skibsted, Wender L. P. Bredie, Michael Bom Frøst, Per Møller, Jens Risbo, Pia Snitkjær, and Louise Mørch Mortensen. Peter Barham is a professor in polymer physics at the University of Bristol, author of The science of cooking and probably doesn’t need further introduction. The Danes are all associated with the Department of Food Science at the University of Copenhagen and have a varied background in chemistry, food science, sensory science and psychology background. Check out the links to their individual profiles more info on projects and publications. Leif H. Skibsted and Michael Bom Frøst head several molecular gastronomy related projects. The Danish scientists also work closely together with Claus Meyer, chef at Meyers madhus and visiting professor at Copenhagen University, and Torsten Vildgaard, assistant head chef at Denmark’s gastronomic shining star Noma (which Claus Meyer started together with René Redzepi in 2004 – they were ranked 3rd in Restaurant magazines top 50 list for 2009, only surpassed by el Bulli and The Fat Duck).

Considering the impact factor of Chemical Reviews (ranked as a clear no. 1 among chemistry journals), this review will likely remain the review on molecular gastronomy for years to come – so you can just as well go ahead and read it. It’s got a whopping 53 pages and more than 350 references, and will be very useful for further studies and research. Oh, and the authors have opted for sponsored access, meaning that you can download the whole review for free!

–

Some curiosa as a post scriptum: Even though the above mentioned review is the most comprehensive academic treatment on molecular gastronomy to this date, the very first mention of “molecular gastronomy” in Chemical Reviews was in a review on platinum chemistry in 2005 (check out the full text search). When writing a review on platinum C-H activation chemistry some years ago with my supervisor I mentioned in the short author bio that besides my research activities I had “a strong interest in molecular gastronomy”. My supervisor prof. Mats Tilset then added to his bio that he had “a strong interest in practical gastronomy”. Even in serious journals there is room for a little fun

I quote the following from the job description:

The professor´s duties will comprise research and teaching in Culinary Chemistry. The professor will have an established track record of research in some area of food science or food chemistry and it is expected that the appointee continues to work in and increase his or hers reputation in that area at the same time as initiating new research. The professor will need to have excellent communication and interpersonal skills.

The appointee should have qualifications within one or more of the following core research areas:

• Observations in professional kitchens to permit the scientific description and subsequent modelling of processes used for cooking of food to optimize gastronomic quality.
• Development of new cooking strategies and methods to be established in restaurant kitchens, domestic cooking and small scale food preparation in general.
• Transfer of knowledge and traditions from cuisines with different historic and ethnic background into a scientific framework with the purpose of design of new dishes and meals.
• Develop food and beverage model systems facilitating controlled flavour and texture development in foods and beverages.
• Explore the creative and artistic interaction between art and science in relation to food and beverages and their combination.

Head over to the Danish site to read the complete announcement text. The deadline for applications is January 5, 2010.

Many cookbooks suggest the following for boiling eggs: 3-6 min for a soft yolk, 6-8 min for a medium soft yolk and 8-10 min for a hard yolk. If you are satisfied with this, there is no need for you to continue reading. But if you’ve ever wondered whether the size of an egg has any impact on the cooking time you should read on. And if you search the ultimate soft boiled egg we share a common goal! From a scientific view point, a cooking time of approximately 3-8 minutes to obtain a soft yolk is not very precise. A number of important parameters remain unanswered: What size are the eggs? Are they taken from the fridge or are they room tempered? Are they put into cold or boiling water? And if using cold water – when should the timer be started? When the heat is turned on or when the water boils? And would the size of the pan, the amount of water and the power of the stove top matter?

A formula for boiling eggs?

I still remember the very first time I heard about a formula to calculate the cooking time for eggs. I was in high school and as a recipe for the ultimate nerd the egg formula gave me a good laugh. Now – many years later – I count myself to this group of nerds And thanks to the internet, google and Peter Barham’s book “The Science of Cooking” – I have been able to find out much more. I haven’t been able to track down the formula I heard mentioned, but the best documented formula nowadays is derived by Dr. Charles D. H. Williams, a lecturer in physics at University of Exeter. He has set up a nice page on the science of boiling eggs and there’s even a pdf with the full derivation of the formula. Given the starting temperature of the egg T_egg, the temperature of the water T_water and the desired temperature T_yolk (all in °C) at the yolk-white boundary, the cooking time t (in minutes) of an egg with mass M (in grams) is given by:

Whenever possible one should use weight measurements in the kitchen, but some times an accurate balance is not available and in those cases we can turn to the Peter Barham’s formula which is published in “The science of cooking”. The circumference of an egg is easily measured around the thick end using a piece of string and a ruler. I used to have a piece of string with three knots at 13, 14 and 15 cm respectively to make it even simpler. The cooking time t (in minutes) for an egg with a circumference c (in centimeters) is given by:

Former colleagues of mine at the University of Oslo have made a nice flash animation to do calculations with Barham’s formula if you’re not too keen to dig out your calculator. Barham states that his formula gives the time for the centre of the yolk to reach the temperature T_yolk whereas Williams mention in the derivation of the formula that it calculates the time for the yolk-white boundary to reach T_yolk. I’m not able to tell whether the formulas actually differ in this respect or not (comments are welcome on this issue!). A comparison of the two formulas for a set of 50 eggs which I weighed and measured shows that for T_yolk = 63 °C and T_water = 100 °C they are quite similar, except for the larger spread of the circumference measurements (see plot below). For higher T_yolk or lower T_water Williams’ formula consistently gives longer cooking times than Barham’s formula. It remains to be seen which of the formulas will be closer to the truth.

The graph shows the cooking time for 50 eggs (sorted by increasing mass) calculated from the mass and circumference using the two formulas shown above with T_yolk = 63 °C, T_water = 100 °C and T_egg = 4 °C. For the given conditions the two formulas give similar results. The most striking lesson learnt is that measuring the circumference is in fact not very accurate, hence the larger spread of these points.

The doneness of the egg depends on the temperature of the white and the yolk. Egg white starts to coagulate in the range 62-65 °C. At these temperatures it is the most heat sensitive protein, the ovotransferrin, which constitutes 12% of the egg white, which coagulates. The major protein of egg white, ovalbumin, makes up 54% of the white and doesn’t coagulate until the temperature reaches 80 °C. The yolk begins to thicken around 65 °C and sets around 70 °C. Further heating to around 80-90 °C produces the crumbly texture typical of hard boiled eggs. Many of these changes are nicely illustrated in the picture of sous vide cooked eggs below, but the changes are also summed up in the following table:

At sea level, the temperature of boiling water is 100 °C. At higher altitudes, the boiling is lowered. As a rule of thumb, the boiling temperature of water is lowered 0.3 °C for each additional 100 m above sea level. For an accurate calculation, check out his calculator. As we shall see later, the formula can of course also be used prepare eggs at sea level, using water kept at temperatures less than 100 °C. Lastly we must know the starting temperature of the egg which will typically be 4 or 20 °C.

Based on T_water = 100 °C, T_egg = 4 °C and T_yolk = 63-67 °C I’ve prepared plots for the range of 50 eggs used in the previous graph. If the circumference or mass of an egg is known, the boiling time in minutes can easily be determined from the graphs. I’ve also prepared downloadable pdfs with the circumference and mass plots.

Cooking time for eggs with given circumference or mass to reach to reach 63, 65 and 67 °C respectively at the yolk-white boundary with T_water = 100 °C and T_egg = 4 °C (click for larger image or download pdfs with circumference and mass plots)

But is this the perfect egg?

No actually not… keep reading! The problem with using boiling water is that while you do heat the yolk to the desired temperature, you have virtually no control with the temperature of the white. If your water holds 95-100 °C, so will the white (or at least the outer most part of the white). This gives it a firm, rubbery texture. So the problem is, to put it differently, that we want to heat the yolk to somewhere above 65 °C, but we do not want to heat the white above 80 °C. The solution to this problem is to “boil” the egg at a temperature lower than 100 °C, which means not to boil it at all but rather sous vide it! Eggs are perfect for sous vide because you can just drop them into the water bath as they are. No plastic bags or vacuum packaging are required. Douglas Baldwin has cooked eggs sous vide for 75 min at different temperatures ranging from 57.8 to 66.7 °C as shown below. Notice how the egg whites and egg yolks change at the different temperatures.

Composite image of eggs cooked sous vide for 75 min at the indicated temperatures (Photo: Douglas Baldwin. Picture used with permission.)

The surprising thing with some of the sous vide eggs is that they are inverted (or opposite boiled). The white is still runny while the yolk is set. If you would like to try this but don’t have a thermostated water bath for sous vide you can improvise a little. The thermostat most people do have in their kitchen is the baking oven (at least those with electric stoves). Preheat your oven to 70 °C. Then heat 1 L of water to 65-70 °C, put the eggs in, cover with a lid and leave the pan in the oven for one hour. The tricky thing here is that oven thermometers are notoriously wrong so use a separate handheld thermometer to check your oven. With some trial and error you should be able to obtain an inverted egg with a runny white and a yolk that has set.

Although scientifically amusing the inverted egg isn’t really desirable form a culinary viewpoint – the white is a little to runny. Regrettably the formulas presented above aren’t of much help either. They fail because they only take time and not temperature into account. The perfect soft boiled egg in my opinion would have an egg white which is heated to around 70-80 °C and a yolk with temperatures ranging from 64 °C at the yolk-white boundary to about 60 °C in the center. I guess it would be possible to prepare such eggs in a sous vide water bath held at 75-80 °C in less than an hour. A further complication of cooking eggs in real life is that they continue to cook when removed from the hot water. Normally this is alleviated by shocking the eggs in cold water, but if cooked at a lower temperature this could possibly be omitted. I will start experimenting to find a perfect mass-time-temperature combination with a time window that’s as large as possible, and I’ll report the results in a future blog post. And these experiments will also include a test of the recipe for eggs cocotte by Joël Robuchon, found via Chubby Hubby’s post on slow-cooking an egg.

Exotic soft boiled eggs

In his book “Off on a comet”, science fiction author Jules Verne shows that he was actually aware of the possibility of “boiling” eggs at a temperature lower than 100 °C. He has correctly observed that water boils at lower temperature in high altitudes, and that on a fictional comet of appropriate mass, water will boil at 66 °C. The temperature is wisely chosen, because by keeping eggs at 66 °C, you really can’t do anything wrong. From the last paragraph of the excerpt it seems that the eggs were not fully cooked after “a good quarter of an hour”. Of course, there is also no mention about the size of the eggs, so any further speculations end here. But I’ll rather leave it to you to read the excerpt from the Gutenberg e-text version – it’s quite amusing:

The skillet was duly set upon the stove, and Ben Zoof was prepared to wait awhile for the water to boil. Taking up the eggs, he was surprised to notice that they hardly weighed more than they would if they had been mere shells; but he was still more surprised when he saw that before the water had been two minutes over the fire it was at full boil.

“By jingo!” he exclaimed, “a precious hot fire!”

Servadac reflected. “It cannot be that the fire is hotter,” he said, “the peculiarity must be in the water.” And taking down a centigrade thermometer, which hung upon the wall, he plunged it into the skillet. Instead of 100 degrees, the instrument registered only 66 degrees.

“Take my advice, Ben Zoof,” he said; “leave your eggs in the saucepan a good quarter of an hour.”

“Boil them hard! That will never do,” objected the orderly.

“You will not find them hard, my good fellow. Trust me, we shall be able to dip our sippets into the yolks easily enough.”

The captain was quite right in his conjecture, that this new phenomenon was caused by a diminution in the pressure of the atmosphere. Water boiling at a temperature of 66 degrees was itself an evidence that the column of air above the earth’s surface had become reduced by one-third of its altitude. The identical phenomenon would have occurred at the summit of a mountain 35,000 feet high; and had Servadac been in possession of a barometer, he would have immediately discovered the fact that only now for the first time,

as the result of experiment, revealed itself to him–a fact, moreover, which accounted for the compression of the blood-vessels which both he and Ben Zoof had experienced, as well as for the attenuation of their voices and their accelerated breathing. “And yet,” he argued with himself, “if our encampment has been projected to so great an elevation, how is it that the sea remains at its proper level?”

Once again Hector Servadac, though capable of tracing consequences, felt himself totally at a loss to comprehend their cause; hence his agitation and bewilderment!

After their prolonged immersion in the boiling water, the eggs were found to be only just sufficiently cooked; the couscous was very much in the same condition; and Ben Zoof came to the conclusion that in future he must be careful to commence his culinary operations an hour earlier. He was rejoiced at last to help his master, who, in spite of his perplexed preoccupation, seemed to have a very fair appetite for breakfast.

There is in fact no need to head off to other planets to find examples of low temperature prepared eggs. If you go to Japan you’ll find onsen tamago which litteraly translates to “hot spring eggs”. Originally baskets of eggs were lowered into hot springs, but the temperature of hot springs vary so I imagine that there were several types of onsen tamago available (does anyone happen to know the exact temperature of the hot springs used?). After cooking the egg is typically cracked into a bowl of dashi soup with mirin and soy sauce. The challenge of preparing onsen tamago eggs at home is accurate temperature control (just as with sous vide in general). One tip I found was to place the egg on top of rice that has just cooked in a rice cooker. Leave the eggs to “cook” for about one hour while the “keep warm” function of the rice cooker is turned on.

Eggs boiled in onsen (japanese: hotspring), Nagano, Japan (Photo: Miya.m. Permission: GFDL, cc-by-sa-2.1-jp).

I’ve been told that in Finland some saunas are equipped with egg racks. Depending on where the rack is placed one could probably chose between hard boiled and soft boiled eggs. But the sauna would have to be kept warm for a long time due to the slow heat transfer from the hot air. And talking about eggs and saunas: If the eggs are placed directly on the hot stones they will not only be hard boiled, but actually turn completely brown and acquire a nutty flavor. In Korea such sauna eggs are known as Maekbanseok gyeran.

Other aspects to consider when boiling eggs

An egg has somewhere between 7000 and 17000 pores, meaning that water slowly evaporates (the density decreases from 1.086 g/cm³ by 0.0017 g/cm³ daily). This is also why eggs age faster at room temperature than in the fridge. Because of the pores, eggs should not be stored next to foods with a strong smell such as onions (unless of course, you want onion flavored eggs). When boiling eggs it is not uncommon that they crack. The most obvious reason is that they are dropped into the water and hit the bottom of the pot. Another reason for cracking is the expansion of trapped air at the blunt end of the egg. This air cannot escape fast enough through the small pores. Conventional wisdom has it that piercing a small hole in the blunt end will let expanding air escape to avoid cracking. It turns out someone has actually scientifically tested this (with 1000 eggs) and their finding was that there was little cracking for fresh eggs, regardless if they were pierced or not. Piercing reduced the cracking of 5-day old eggs and totally eliminated cracking of 28-day old eggs. The authors theorize that the air pocket grows due to evaporation (meaning there is more air to expand) and that the egg shell of fresh eggs is porous but that the pores gradually become clogged upon storage. Curiously the abstract concludes with the following sentence (this was written in 1973, but it’s still quite unusual for a scientific journal):

Housewives should pierce eggs before boiling them, since if they are fresh it will do no harm and if they are stale it will prevent splitting.

We can safely assume that the advise holds true for men as well! Apart from piercing holes to avoid cracking it is possible to reduce the potential damage from cracking by addition of salt or vinegar to the water. This will help the egg white coagulate faster and thus plug any crack formed.

Picture of egg shell pore (Photo: Jim Ekstrom. Permission: Freeware for non-commercial use).

If you’ve read this far, make sure to also read how the egg yolk problem was finally solved and my follow up post with pictures and a video of egg yolk cooked at 63.0 °C for 40 to 155 minutes!

I had a wonderful trip to Brugge/Bruges to attend the foodpairing seminar The Flemish Primitives. I got to meet many interesting people including Heston Blumenthal, Peter Barham, Andrew Dornenburg, Karen Page, Ben Roche and Tony Conigliaro to mention a few. I also finally had the opportunity to talk to my fellow Swedish food bloggers Lisa Förare Winbladh (Matälskaren, Swedish only but Google can translate) and Malin Sandström (Matmolekyler, Swedish only but Google can translate) who’ve recently been awarded money to write a Swedish book about molecular gastronomy for home cooks. I even talked to several people who read Khymos! It’s always nice when I can attach some faces to the crowd out there in the big, unpersonal blogosphere.

As you see from this long post the day was packed and believe it or not – there will be a couple more posts in the next few days. One on the surprise “chocolate box” (for me this was the highlight), a summary of the interview with Heston Blumenthal and some info on the chemistry behind the glowing lollipops! I’ll also try do dig up the recipe for the chocolate dip that came with our lunch fries.


In case you wondered: Peter always wears penguins!

Peter Barham (physicist, author of The science of cooking) started the day by giving an introduction to the scientific approach to cooking. Cooking started a lot of science, and chemistry (and alchemy) has origins that can be traced back to the observation of how food changed when cooked. And as a side note: even the word chemistry is linked to food through the greek word Khymos Until about 100 years ago there was a clear link between cooking and chemistry, but then came a period where scientists mostly did not bother much about food. Until Nicholas Kurti entered the scene: that’s the guy who said that “I think it is a sad reflection on our civilization that while we can and do measure the temperature in the atmosphere of Venus we do not know what goes on inside our soufflés”. Four examples were used to illustrate how science can help chefs.

1) Conflicting reasons are given for why salt should be added to blanching water to retain the green color of vegetables. Contrary to popular belief salt does not raise the boling temperature of the water with more than a fraction of a degree. Science tells us that there really isn’t any good reason for adding salt to the water when blanching vegetables.

2) Science also provides insight to what happens when we heat up meat. When heated the meat first gets tougher. At around 40-45 °C the meat proteins start to denature, and at 55 °C the meat goes from tender to tough. Prolonged heating above 55 °C however will cause the collagen to dissolve into soft gelatin.

3) Thanks to science we now have a vide range of gelling agents (or hydrocolloids if you like) available for use in the kitchen. They can be used to create gels that are hard, soft, tough, elastic, brittle, hot and so on. We can also explain the crunchy and crispy texture of caramel which technically is classified as a “glass”. And we can also understand why ice cream has such a soft texture. This has to do with the very small size of the solid particles in ice cream (they’re typically < 1/10 mm). And a very nice way of achieving this is by making the ice cream with liquid nitrogen so it freezes very fast.

4) Science helps us understand what flavor is and how we perceive flavor using all our senses. For instance our memory plays an important role when our brain interprets a flavor. Your history of eating will influence how your next meal tastes! Sight is also extremely important. This can easily be demonstrated with some white wine and blue/red food coloring. If an unsuspecting subject is asked to describe “white” white wine and white wine colored with blue and red food coloring the descriptions will probably be typical of a white and red wine. Even if you know your are drinking a red colored white wine it is hard to believe that it is the same wine. The color of plates also influences our perception of flavor, so most people find eating from a blue plate unpleasant. Sound influences how we chew and a crunchy sound actually stops our jaws from closing to fast. If the chewing sound is played back with a 0.5 second delay it is almost impossible to eat! It has also been shown that the beat of music influences how fast guests chew, and apparently there is a restaurant in Australia that utilizes this. It has also long been known that touching sand paper or smooth skin can affect the texture of what we eat.

Andrew Dornenburg and Karen Page

Next up were Karen Page and Andrew Dornenburg who presented several of their bestselling books on cooking and flavor, including Culinary Artistry, What to Drink With What you Eat and The Flavor Bible. They made an important point that cooking is the sum of ingredients and technique/preparation. Food science and molecular gastronomy has provided a lot of information on technique, and the example par excellence is Harold McGee’s On food and cooking. However, for ingredients and flavor pairing in particular there hasn’t been any authoritative source available, forcing chefs to cross read a number of cookbooks when looking for new flavors and pairings. It was this realization that motivated them to write Culinary Artistry which is really a thesaurus of classic pairings. I can testify to it’s usefulness – and one example I’ve presented here on the blog are the cherry jams I made with pepper and other spices. Their most recent book, The Flavor Bible, is an updated and expanded edition of Culinary Artistry which includes and reflects the changes in consumer preference in the last decade.

I have emailed a litte with Karen and Andrew previously and got the opportunity to chat with them in the break. – We’re excited to learn about new approaches to flavor pairing, Karen let me know. Andrew added that they hadn’t had the opportunity yet to sample molecularily based food pairings before so they we’re looking forward to try this.

Lorenzo Cerretoni gave a presentation about flavor compounds in olive oil and how they can be paired with Mantis shrimp. After this informative, yet slightly less inspiring talk the Belgian chef Bart de Pooter presented his 4 taste model and how he uses this as a creative approach to create dishes and menus. One concept he promoted was to use ingredients from the same environment. A pheasant for instance walks on grass and eats maize and carrot, so naturally it could also be served together with flavors such as grass, maize and carrot. He also talked about physical and psychic needs and gave a slightly wrong explanation of the flavor pairing hypothesis.

In fact during the whole day there was no proper scientific explanation and discussion of the hypothesis, but Bernard Lahousse – project leader of The Flemish Primitives – did give a popularized version of the hypothesis and an account of how it all started. He explained how the Firmenich scientist François Benzi first stubled across a new way of pairing foods. At one of the Erice meetings he smelled jasmin in a garden and being a flavor scientist knew that this smell was mainly due to indole. Knowing that pork liver also smells of indole he got the idea that jasmine and pork liver might taste nice together – and they did! Bernard did show a picture of a GC-MS and explained how the University of Leuven has been doing food analyses and that only odors with concentrations above the odor thresholds were taken into account. Since he didn’t mention odor activity values (OAV) specifically I asked Bernard about that later and he confirmed that all the data in the food pairing website are now based on odor activity values. Since the first version of the food pairing web site was based on concentration and number of odorants I would expect that this would change some of the pairing charts and Bernard confirmed that this had been the case.

For the event 10 chefs where each given a food product from one of the sponsors. These products were then analyzed and a list of suggested pairings was provided to all the chefs. It should be mentioned that these were top class chefs, but I have to admit that watching chefs cook in real time actually became quite boring after a while, especially since some of the dishes needed seemingly endless steps of preparation. For most of the preparations presented it was also very unclear which of the ingredients used were picked based on the flavor pairing and which were picked by the chef to complete the dish. But the dishes looked absolutely wonderful! Too bad we couldn’t sample them I found two of the dishes particularily interesting (and I think the recipes will be made available on the web). Sang Hoon Degeimbre, chef at L’Air du temps had chosen Leffe beer, but instead of doing a flavor pairing he did a flavor substitution. To achieve this he used several ingredients (shown in the figure below) which when combined would resemble Leffe. In fact he made a dish completely without Leffe that was intented to taste like Leffe – it’s hard to say whether he succeeded or not, but the concept is very interesting! And what warmed the heart of an organic chemist was that Sang Hoon had equipped his kitchen with an erlenmeyer flask and used a glass syringe (looked like a luer lock Hamilton type syringe to me).

Figure from food pairing website. (C) Creax 2008.

The food pairing I found most interesting was the one with Oud Brugge (a cheese), coffee and vanilla. To bind these flavors together chef Gert de Mangeleer from Hertog Jan used potatoes. The surprising element of the dish was the coffee – he sprinkled his dish with freshly ground coffee. The vanilla was applied as a grape seed oil extract of natural vanilla – a nice example of how oil can be used for flavor extraction.

Ben sitting on the stage watching his own video.

- If Einstein had been a chef, he’d probably be like Ben Roche, said presenter Gene Bervoets. Ben is the pastry chef at Homaro Cantu’s Moto restaurant in Chicago – it’s the restaurant where you can chose between a 10 and 20 course menu and then start your meal by eating the menu. Ben’s topic was the Chicago style hot dog and he started off by presenting a mind map of this, resembling the food pairing charts at the food pairing website. Most of his presentation was in fact prerecorded video clips which were really entertaining! His deconstruction/construction of the Chicago style hot dog resulted in a chips & salsa. Evolution of flavor turned the hot dog into pop corn (“less calories than when eating the hot dog”) sprayed with hot dog infused oil and sprinkled with freeze dried garnish. Translation of culture resulted in a Mexican version of “encased meat” using chorizo and a soft taco shell. This dish was also made into a dessert version. Lastly the hot dog was transmogrified into a cartoon dessert version with strawberry sorbet, mint and pistacchios. Hopefully the videos will be made available, but in the mean time you can check out the video of Ben at Taste3.

Although we couldn’t sample the chef’s preparations there a number of tasting samples of different food pairings available in the breaks:

Of these my favorites were the almond thins with mozzarella, fig and ham, and the cooked beef with peanut, chocolate vinagrette and peas. The potato cream was nice, but was a litle overpowered by to much cheese.

Baked beef, cream of peas, peanuts and vinagrette with 70% chocolate

The program session was closed by Albert Adria, younger brother of Ferran Adria. He showed stunning pictures from his coming book natura, accompanied by videos showing how the different elements of the dishes are created. He also showed a short teaser documentary for A day at el Bulli.

Next year’s meeting will be devoted to tools, including one which was presented at the very end of the day with music, ballet dancers and fire works: a reinvention of Ford’s assembly line for mass production of haute cuisine.

The avalanche of books in the food/science intersection this fall has been truly amazing. Three books in particular have showcased special restaurants: el Bulli, Alinea and The Fat Duck.

I own the first two and both – in different ways – are very satisfying. In line with previous releases from Ferran Adria, A day at el Bulli is extremely thorough at documenting exactly that – a complete day at the restaurant, with minute-by-minute photographs. It’s all very appealing – and you’ll be surprised by all the recipes that are included! The nice thing about this book is that it serves both as a coffee table inspirational book (for us geeks), but also as a great resource for those who are professionally involved.

The Alinea book is not as documenting in it’s style, but the level of detail and sophistication does not stand back from that of el Bulli. And the number of recipes included and details described is amazing. It has a very nice and useful index with main ingredients pointing you to the respective recipes, so if you want to cook with walnuts for instance, the index immediately tells me that there are eight recipes to chose from. And even though each single dish/presentation typically includes 3-5 separate recipes; for an amateur like me it’s perfectly fine to extract only one of the recipes from a presentation and turn that into a dish on it’s own.

The Big Fat Duck Cookbook is still on my wish list – I expect to receive it in January and I’m truly looking forward to that. The reviews have been great and – well – there’s probably a lot more to say about a book that weighs more than than 5 kg, but I’ll leave it there!

Apart from these three books it’s hard to get around Under pressure by Thomas Keller, especially when considering that I got my immersion circulator the other day. It’s a book completely devoted to sous-vide cooking, written by one of the pioneers who elevated sous-vide from a convenient boil-in-bag method to the realms of gastronomy. Many (most?) of the recipes are not suited/intended for normal everyday cooking – at least if you depend on a regular grocery store like mine that doesn’t stock rabbit, quail and squab. But you’ll be surprised by how many recipes he includes for vegetable and fruit sous-vide!

Apart from these must-have books I’d check out the following books which would be recommended Christmas gifts for those interested in food or science or both. The title The Hungry Scientist Handbook immediately caught my attention (just like anything does that combines food and science). According to the description in includes more than 20 DIY projects ranging from edible origami to glowing lollipops and cryogenic martinis. O Boy! I can’t wait till I receive my copy

For those looking for a gift that combines science with Christmas I can warmly recommend the classic Can Reindeer Fly?: The Science of Christmas. In an entertaining and light hearted style topics such as the psychology of giving, the laws of shopping and the thermodynamics of turkey preparation are covered. And the most important question of all – how does Santa manage to deliver all those presents in one night? – is also answered in a proper scientific manner. I can only recommend this book – it’s the perfect Christmas gift for anyone who needs to be (or already is) convinced that science can be fun!

And then there are all the classics of course: On food and cooking, CookWise (now supplemented by BakeWise), The Science of cooking, Molecular gastronomy – exploring the science of flavor and Kitchen Mysteries – Revealing the science of cooking. You can find many more suggestions over at the static pages in the section molecular gastronomy.

If you’re looking for for a true gift-for-geeks you can buy a printed copy of “Texture – A hydrocolloid recipe collection” for only $4.95 + shipping from lulu.com, a print on demand company. It’s current sales rank is #104,208 so I don’t expect it to found under very many Christmas trees You can of course also download the pdf at no cost!