A couple of books have caught my eye during the year and have naturally made their way into my Christmas wish list (and some I’ve already ordered myself). Please let me know if there are books you belive should be on this list that I have missed.

Culinary Reactions: The Everyday Chemistry of Cooking
by Simon Quellen Field
288 pages

The back cover states “When you’re cooking, you’re a chemist!”. I couldn’t agree more and figured this was a book for me. I already have my copy in front of me and see there are many interesting observations and experiments described.

Heston Blumenthal at Home
by Heston Blumenthal
408 pages

The Family Meal: Home Cooking with Ferran Adria
by Ferran Adrià
384 pages

Ferran and Heston have jumped onto the cooking-at-home-with-great-chefs waggon. They’d be more than welcome to come and cook in my kitchen, but until that happens I’ll let their books inspire me. An important thing about these books is that, given their close collaboration with scientists, I have a high expectation that the advice given in all recipes should be scientifically sound (which of course is not the case for many other cook books).

Neurogastronomy: How the Brain Creates Flavor and Why It Matters
by Gordon M. Shepherd
288 pages

I stumbled across this one by chance. It looks like a “must have” too me, and my copy is already on its way. In an interview with Salon, the author Gordon M. Shepherd, a professor of neurobiology at the Yale School of Medicine, says that:
“I began to realize that increasingly smell was for sensing the flavor of food. It goes almost unrecognized as we eat our food because we think it all comes from taste in our mouths. The more research that I did on flavor, the more I realized that the sense of smell was the dominant sense in flavor — and that we are almost totally unaware of it.”

The Oxford Companion to Beer
edited by Garrett Oliver
960 pages

Having ventured into brewing I found this book quite irresistable!

The Kitchen as Laboratory: Reflections on the Science of Food and Cooking
edited by Cesar Vega, Job Ubbink and Erik van der Linden
336 pages

I’ve mentioned this book previously. With 35 essays covering a range of topics this should be of interest to many Khymos readers!

Apart from these books we just have to face it: there’s no way around Modernist cuisine. If you don’t own a copy yet I’m quite sure it still sits there on the top of your wish list. And – if you happen to read Swedish – I would highly recommend the recently published book Matmolekyler (“Food molecules”) by Malin Sandström and Lisa Förare Winbladh (also check out their blog blog with the same name – also in Swedish).

A book I’ve been looking forward to for a long time is The Kitchen as Laboratory: Reflections on the Science of Food and Cooking. It is now available for pre-order with expected delivery on January 31st, 2012. Work on the book began back in 2008, and that year coincidentally marked the 20th anniversary of But the crackling is superb, a refreshing anthology on the science of cooking and eating edited by Nicholas and Giana Kurti. The editors of The Kitchen as Laboratory, Cesar Vega Morales, Job Ubbink and Erik van van der Linden, wanted to continue in the spirit of this book. Through 35 essays the invited chefs, scientists and cooks explore topics of their choice, often based on experiments in their own kitchen. This includes a contribution by me on the Maillard reaction and how we – often without thinking about it – increase it’s rate in different ways when cooking. As for the other contributions, based on the preliminary lists all I can say is that I look forward to read the book!

My immersion circulator is working again! And the first thing I decided to do was to cook eggs at 63.0 °C for 40, 60, 75, 110 and 155 min and show you the results. If you read my last blog post on Perfect egg yolks or have stumbled across the paper Culinary Biophysics: on the Nature of the 6X°C Egg you may recognize that these times correspond to egg yolks with textures similar to sweetened condensed milk, mayonnaise, honey, cookie icing and Marmite respectively. I used the iso-viscosity graph from the paper mentioned to determine the cooking times as shown below.

The figure shows how cooking times at 63.0 °C are determined to achieve different textures. (The figure is used with kind permission from Springer Science+Business Media: César Vega and Ruben Mercadé-Prieto in Food Biophysics 2011, 6:152-159, Culinary Biophysics: on the Nature of the 6X °C Egg, figure 8, page 158. The legend overlay has been added by me for clarity.)

As the individual eggs reached their cooking times they were held in cold water until the last egg was finished. I then cracked all the eggs and took the pictures below to illustrate the differences in textures. I think the picture speaks for itself. The amazing thing is that the only difference between the eggs is the cooking time!

It can be difficult to judge textures properly from still photos, so I also shot a few video clips to illustrate the texture of the 40, 75 and 155 min eggs (by the time I shot the videos the yolks had become more viscous, possibly due to cooling and/or evaporation). The texture ofthe 155 min egg yolk was perhaps the most fascinating with a tremendous plasticity. There must be some exciting culinary uses for this!

If an egg is to be served by itself one will typically also want to set the white. There was a question about this to my previous post, and a reader even tried with 2 min pre- or post-boil. Without cooling the difference between pre- and post-boil was quite significant as evidenced from the pictures. I did a similar experiment but cooked the eggs at 63.0 °C and opted for a 3 min pre- or post-boil with the small difference that I cooled the egg back to room temperature after/prior to the pre-/post-boil to avoid any interference between the 63 °C and 100 °C treatments. This worked very well and I wasn’t able to detect any difference between the pre- and post-boiled eggs.

It doesn’t matter if you pre- or post-boil your egg as long as you cool it to room temperature inbetween the boiling water and the temperature controlled water bath.

In 2009 I wrote about my journey towards the perfect soft boiled eggs. Equipped with a formula I knew what I wanted, but it wasn’t so easy after all. Since then I’ve tried to model experimental data from Douglas Baldwin as well as data from my own measurements of egg yolk tempereatures when cooked sous vide (pictures of how I did this at the end of this blog post). I never got around to blog about the results, and now there’s no need for it anymore: The egg yolk problem has been solved! And the question that remains is: How we can utilize this in the kitchen?

The break through came this year with a paper by César Vega and Ruben Mercadé-Prieto entiteld Culinary Biophysics: on the Nature of the 6X°C Egg [1]. In my opinion it’s a brilliant example of molecular gastronomy: the results are practical enough for chefs and technical enough for scientists. This paper holds the key to unlock the true potential of egg yolk texture, and with it every chef can reproducibly prepare yolks with textures in the whole range between soft and hard. If you think I sound a bit exalted, you’re absolutely right.

Eggs cooked at low temperature have been all around the internet for the last couple of years, but a general feature of all these posts has been a focus on temperature. This has been the generally accepted truth. Even Hervé This in an interview with Discover magazine claimed that “Cooking eggs is really a question of temperature, not time”. But the present paper counters this. It’s main conclusion is that the texture of the egg yolk is a result of the time-temperature combination used, it’s thermal history if you like. If you’re interested in the details of the paper I suggest you jump directly to the pdf (I could download it for free some days ago, so give it a try), but if you’re only interested in the results, read on! A practical way to measure egg yolk texture is by using a rheometer. It’s a fancy piece of equipment that measures viscosity (and for those of you who are technically inclined – it measures viscosity as a function of shear rate). And what César and Ruben have done is to prepare a graph that shows the viscosity of a large number of temperature and time combinations. It’s a so-called iso-viscosity plot, meaning that once you have decided which viscosity you want the graph will show you all the temperature-time combinations that will give the desired result.

The figure shows how an egg yolk with a texture resembling one of the reference foods can be prepared by chosing any temperature-time combination along the respective plotted lines. (The figure is used with kind permission from Springer Science+Business Media: César Vega and Ruben Mercadé-Prieto in Food Biophysics 2011, 6:152-159, Culinary Biophysics: on the Nature of the 6X °C Egg, figure 8, page 158. The legend overlay has been added by me for clarity.)

For chefs, and even for chemists not working with rheology, it’s difficult to relate to numerical values of viscosity. To get around this the authors did a clever thing by measuring the viscosity of a range of semi-solid foods that may function as reference points: sweetened condensed milk, mayonnaise, honey, cookie icing and Marmite. You can use the iso-viscosity plot shown above to find different time-temperature combinations that give the same yolk viscosity. To use the plot, first decide which texture you want the egg yolk to have. Let’s say you’re in for a honey like texture (filled triangles). Pick a temperature, draw a vertical line until it crosses the line plotted through the triangles and then a horizontal line from there to the time axis. Repeating the exercise for different temperatures will give the different time-temperature combinations that all give a honey like yolk texture; in this case 310 min at 60 °C, 200 min at 61 °C, 125 min at 62 °C, 75 min at 63 °C, 55 min at 64 °C, 45 at 65 °C, 40 min at 66 °C, 26 min at 67 °C and finally 25 min at 68 °C will all do the trick. With a temperature controlled water bath one can chose whatever combination one likes, but if using a large pot of water and manually turning the heat on/off it’s advisable to cook the egg yolk in the lower temperature range. Also, the authors state that it requires a bit of practice to obtain different textures at temperatures above 66 °C.

The paper only deals with egg yolks. At the given time-temperature combinations the white will remain more or less runny. If only the yolk is to be used this doesn’t matter. But if serving the whole egg a simple way to set the egg white is to immerse the egg in boiling water for 2-3 minutes. Alternatively for a little longer at 85 or 90 °C. A comment made by Olly Rouse to my previous post on eggs suggests 8 min at 90 °C followed by cooling at 55 °C is perfect to set the white. However, if the eggs are to be “cooled” at 6X °C maybe 6-7 min is enough. What complicates matters even more is that at 6X °C convection inside the still runny egg white contributes significantly to the heat transfer, but I assume that this is negligible in combination with the longer cooking times in the lower 6X °C range.

Now that all possible egg yolk textures are available the question is: How we can utilize this in the kitchen? Apart from preparing soft boiled eggs, are there any applications in cooking? I’m sure there are many good ideas out there just waiting to be realized. If you blog or twitter about your ideas for utilizing precisely cooked egg yolks I suggest that you tag your blogposts with 6Xyolk and your tweets with #6Xyolk. Then everyone can easily follow up on the progress.

From my own experiments with measuring the core temperature of eggs cooked sous vide: The pictures show how I cut a thin slice from a plastic wine cork, pierced it with a philips screw driver, glued it to an egg, carefully pierced the egg shell with the same screw driver and finally introduced a thermocouple into the core of the egg yolk. There was enough friction between the thermocouple and the wine cork to allow the egg to be suspended by the thermocouple in the water bath. Temperature was logged using myPClab from Novus. Prior to the measurement the egg with the inserted thermocouple were left for several hours in the fridge for temperature equillibration.

[1] Vega, C.; Mercadé-Prieto, R. Food Biophysics 2011, 152-159. DOI: 10.1007/s11483-010-9200-1

Molecular gastronomy: a food fad or science supporting innovative cuisine? Cesar Vega, Job Ubbink (Trends Food Sci Technol 2008, 19(7), 372-382)

The concepts, history and approaches of molecular gastronomy are discussed with an emphasis on the relation to food science and technology. A distinction is made between molecular gastronomy and science-based cooking (…) We discuss how chefs are dealing with the available systematic knowledge on food and cooking, and how molecular gastronomy can facilitate the cumbersome, but much needed discussions among food scientists and chefs.

Molecular Gastronomy: A Food Fad or an Interface for Science-based Cooking? Erik van der Linden, David Julian McClements and Job Ubbink (Food Biophysics, 2008, 3(2), 246-254)

A review is given over the field of molecular gastronomy and its relation to science and cooking. We begin with a brief history of the field of molecular gastronomy, the definition of the term itself, and the current controversy surrounding this term. (…) On the one hand, it can facilitate the implementation of new ideas and recipes in restaurants. On the other hand, it challenges scientists to apply their fundamental scientific understanding to the complexities of cooking, and it challenges them to expand the scientific understanding of many chemical and physical mechanisms beyond the common mass-produced food products.

The life of an anise-flavored alcoholic beverage: Does its stability cloud or confirm theory? Elke Scholten, Erik van der Linden, Hervé This (Langmuir 2008, 24(5), 1701-1706).

The well-known alcoholic beverage Pastis becomes turbid when mixed with water due to the poor solubility of trans-anethol, the anise-flavored component of Pastis in the water solution formed. This destabilization appears as the formation of micrometer-sized droplets that only very slowly grow in size, thus expanding the life of the anise-flavored beverage. (…) experiments on Ostwald ripening show an increase in stability with increasing ethanol concentration, the results based on our interfacial tension measurements in combination with the same Ostwald ripening model show a decrease in stability with an increase in ethanol concentration.

Formal descriptions for formulation, Hervé This (Int J Pharm 2007, 344(1-2), 4-8)

Two formalisms used to describe the physical microstructure and the organization of formulated products are given. The first, called “complex disperse systems formalism” (CDS formalism) is useful for the description of the physical nature of disperse matter. The second, called “non periodical organizational space formalism” (NPOS formalism) has the same operators as the CDS formalism, but different elements; it is useful to describe the arrangement of any objects in space. Both formalisms can be viewed as the same, applied to different orders of magnitude for spatial size.

Lavoisier and meat stock Hervé This, Robert Meric, Anne Cazor (Compt Rend Chim 2006, 9(11-12), 1510-1515).

Antoine-Laurent de Lavoisier published his results on meat stock’ preparations in 1783. Measuring density, he stated that food principles’ were better extracted using a large quantity of water. This result was checked.