Archive for the ‘tips & tricks’ Category

Ginger milk curd

Monday, February 24th, 2014

ginger-milk-curd-syneresis
With only 3 ingredients you can make a tasty gel within minutes. The gel is very fragile and easily “looses” liquid, in this case whey, which is seen as a clear drop under the spoon. This loss of liquid from a gel is known as syneresis.

Some weeks ago, while doing research for Texture on gel formation in foods where no “external” hydrocolloid is added, I came across ginger milk curd (in Chinese: 姜汁炖奶/薑汁撞奶). With only three ingredients – milk, ginger and sugar – it immediately caught my attention. I found a recipe and my first attempt was successful. I was amazed! With three seemingly simple ingredients I was able to form a tender, fragile gel within minutes. I loved the strong ginger taste with a touch of sweetness. After my first success I had several failed attempts, so I looked up some more recipes. What puzzled me was that, as I dug up more recipes, the different instructions were specific, but also contradictive. I couldn’t let go at this point, so I continued reading – also scientific papers. Now that I have a fairly good understanding of the science behind ginger milk curd it is clear that the many recipes I had found were full of kitchen myths. (more…)

Texture updated and available for download

Saturday, February 15th, 2014

tv30-cover

I’m happy to announce that a major update of “Texture – A hydrocolloid recipe collection” is now available for download. Version 3.0 of Texture features many new recipes, , more pictures (A big THANK YOU to all contributing photographers!), a new chapter on non-hydrocolloid gels + many minor additions and corrections. Given the many recent books about molecular gastronomy and modernist cuisine I have certainly asked myself: Is there a need for a revision of Texture? Since you read this I obviously landed on a “yes”. As a toolbox for chefs and amateur cooks I still believe that this collection is unique for several reasons: the ranking of recipes according to the amount of hydrocolloid used, the texture index and the total number of recipes (339 in total). To the best of my knowledge no other cook books have taken the same approach to collect and systemize recipes this way. And judging by the feedback I have received many chefs and food enthusiasts around the world have found Texture to be a useful resource in the kitchen (to which the 80.000 downloads from Khymos alone also testify). I do not regard Texture as a competitor to the numerous books available, but rather as a supplement. Inspiration for cooking is best sought elsewhere, but if Texture can inspire to experimentation with the texture of foods I believe it has fulfilled its mission.
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Volume-to-weight calculator for the kitchen

Thursday, January 23rd, 2014

glasbake-measuring-cup

Vintage Glasbake Measuring Cup by Gerrilynn Nunley

Despite the fact that the U.S. Metric Association have advocated metrication for nearly 100 years, many cookbooks still use US customary weights and volume measures. When following a recipe calling for teaspoons, tablespoons, fluid ounces, cups, pints, quarts or even gallons, I’ve often found myself using conversion websites such as Convert-me, picking ingredients from a list and entering the amount and unit. This works OK for single ingredients, but is less practical when converting a complete recipe. I therefore made a calculator to convert volumetric units to grams based on densities of a range of common ingredients. It has greatly simplified the task for me, and perhaps you’ll find it useful as well?

Download calculator (more…)

Brining salmon to avoid formation of white exudate

Sunday, January 5th, 2014

salmon-unbrined-brined
Avoid the white exudate (left) by brining salmon (right) prior to cooking

Salmon is a wonderful fish that can be prepared at nearly any temperature between raw (as in sushi) and fully cooked. In between these extremes lies a range of temperatures that with the advent of sous vide have become accessible for more and more (try for instance salmon confit: 18 min @ 42°C). Beyond temperature salmon can be combined with salt, sugar, acids, liquorice or even smoke. And the more adventurous even leave it to ferment for a couple of days to yield a gravlax (which used to be fermented, but today normally is only cured) or – for the strong hearted – rakfisk (which is still produced by fermentation). But exotic preparations aside. A problem encountered when heating salmon is the liquid that oozes out as the muscle is heated, and solidifies once it hits a hot surface. (more…)

Merry Christmas to all geeks

Friday, December 20th, 2013

cookie-cutter-2

Some say 2012 was the year when 3D printing hit the mass market. Well, here’s my small contribution based on my own christmas tree design as well as the classical Penrose kite and dart. (I know. It’s 2013 now, but the cookie cutters were actually printed in 2012!) As a follow-up to my post on cookie tessallations a friend helped me print cookie cutters so I could make ginger bread cookies with a minimal waste of dough. The files needed for printing can be downloaded (more…)

Gastrophysics symposium in Copenhagen

Sunday, September 9th, 2012

On August 27-28 the symposium “The Emerging Science of Gastrophysics” was held at the Royal Danish Academy of Sciences and Letters in Copenhagen. The symposium poster said “interdisciplinary”, and with presentations by scientists in fields ranging from physics and chemistry to neuroscience and psychology I think it lived up to its name. In this post I share with you what I found interesting and useful from my own, subjective perspective. I must admit that I didn’t understand everything presented. Perhaps this is even a general challenge for the whole field. It illustrates how difficult it is to do science that is simple enough for chefs to understand yet scientific enough for scientists. César Vega and Ruben Mercadé-Prieto’s study on egg yolks is perhaps one of the best examples of a paper that manages to balance the two. A couple of the presentations were very successful at this, and I think that if we continue to meet at similar symposiums we will see many more papers that manage to catch the attention of chefs and scientists at the same time.

Throughout the symposium (more…)

Recreational kitchen mathematics: Cookie tessellations

Thursday, January 19th, 2012


Is there a way to avoid all that extra dough in between the cookies? (Photo: Christmas Tree Cookie Cutter from Bigstock)

It should come as no surprise that food, chemistry and mathematics meet in baking. For once I will leave the chemistry aside for a while and turn to the mathematical aspects of baking. More precisely I will delve into geometrical problems encountered in baking. When cutting cookies from a rolled out dough or placing cookies on a sheet for baking you actually attempt to solve a mathematical problem known as a packing problem. The purpose is to maximize the distance between the cookies and maximize the size of the cookies, paying attention that the cookies should not touch. Many will perhaps start with a square packing (see below), but soon figure out that a hexagonal packing will fit even more cookies onto the rolled out dough or onto the baking sheet (especially when the dough/sheet is large compared to the cookies). The optimum way of placing 2-17 circles in a square are shown below (and the solution for up to 10.000 circles is also available).

My challenge for you however is a different one as I’m interested in eliminating the leftover dough when cutting cookies. To achieve this the cookies cannot be circular. Using a square cookie cutter (or simply a knife) would be the easiest way to leave no gaps, but how cool are square cookies? What I’m really looking for are cookie tessallations which are aesthetically pleasing, and at the same time transferable to a baking sheet. Oh yeah: a tessallation “is the process of creating a two-dimensional plane using the repetition of a geometric shape with no overlaps and no gap” according to Wikipedia. So – no gaps – no leftover cookie dough! (more…)

Mineral waters à la carte

Wednesday, January 4th, 2012


Cloning popular brands of mineral water is now simpler then ever before with the updated version of the mineral water calculator!

When I blogged about DIY mineral water last year it was mainly a theoretical exercise since I didn’t have the required salts at hand. My experience was limited to adding some baking soda (sodium bicarbonate) to water before carbonation. Luckily Paul Hinrichs tested the calculator! In the meantime I have purchased the required salts and with several kilograms in total I’m probably well stocked for the next decade! Based on the output from the calculator, I mixed the salts required to clone San Pellegrino, added water and carbonated the mixture. And the good news is that it works! The water tastes great and I’ve been enjoying cloned mineral waters every day now for the last couple of weeks.
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Book review: Cooking for geeks

Monday, June 13th, 2011


Jeff working on a recipe in his kitchen. (Photo by Shimon Rura. © 2009 Atof Inc.)

For a book about food this is a rather unusual book. The author states in the preface that the goal of the book is to “point out new ways of thinking about the tools” that are found in the kitchen. It’s not a book you’ll pick up for its recipes, even though the 100+ recipes included are fine. And it’s not a book you would pick up because of mouthwatering photographs of food. It is however a book that could trigger a lifelong interest in cooking among those who are scientifically minded. Where an experienced chef can read between the lines of a recipe, the rest of us can turn to books like Cooking for geeks to get hints on how to turn a recipe into a tasty dish.
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Perfect egg yolks

Monday, April 18th, 2011


Maybe I have a hangup on soft boiled eggs, but I’m deeply fascinated by how something simple as an egg can be transformed into such a wide range of textures. I’m talking about pure eggs – no other ingredients added. Playing around with temperature and time can result in some very interesting yolk textures – yolks that are neither soft nor hard, but somewhere inbetween. Two examples from the blogosphere are Chad Galliano’s 90 min @ 63.8 °C egg yolk sheets and David Barzelay’s 17 min @ 70.0 °C egg yolk cylinders (both bloggers giving credit to Ideas in food and Wylie Dufresne respectively).

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 (more…)