An updated version of “Texture - A hydrocolloid recipe collection” is now available for download (version 2.1). The version includes corrections of typos, minor additions to the property tables plus an important update in the gelatin section and a recipe for agar filtration. Read on for details!

I’m grateful for feedback from several readers pointing out that the size of gelatin sheets is made to compensate for different bloom strengths. In other words, one gelatin sheet will gel a given amount of water, regardless of the size of the gelatin sheet. To the best of my knowledge, this convention seems to have been adopted by most gelatin producers.

All gelatin based recipes have been updated to reflect this and most of them now give the amount of gelatin both in grams (for a platinum type, 240 bloom gelatin) and in number of sheets. I’ve also included a formula for conversion between different bloom strengths. This formula differs from what has been published earlier (no square root), but by testing the formula for given gelatin sheet bloom strengths and weights I got better results by simply multiplying the mass by the ratio of the bloom strengths. If you know more about these formulas, please leave a comment or email me.

Checking the gelatin recipes I discovered that the recipe “Strawberry spheres” originally called for “Sosa vegetable gelatin” which is not gelatin but a mixture of carrageenan and locust bean gum which are dispersed with maltodextrin. Since the exact amount of carrageenan and locust bean gum are not known I’ve deleted the recipe (but I’m sure you could achieve the same coating effect with plain gelatin, perhaps a 3-4% solution to render it viscous so it will cling the the spheres).

Thanks to feedback from a reader there is also recipe now for agar filtration (based on a Spanish forum post). This works just like gelatin filtration, but is much faster. Apparently you get more or less the same results with regard to clarity, flavor and color.

If printing the collection, make sure the hydrocolloid properties table is rotated so it prints correctly. This table is presented in landscape format. The right most column of the first page is gelatin - if you don’t see it, try printing these pages again. The pages are optimized for printing on A4. If printing on Letter sized paper, make sure you check the “resize” or “fit to paper” option in your pdf reader.

Thank you for comments, corrections, recipes and other feedback! As always, I can be reached at webmaster a t khymos d o t org.

9. Keep a written record of what you do!

Wouldn’t it be a pity if you couldn’t recreate that perfect concoction you made last week, simply because you forgot how you did it? Last year I made a vegetable soup to which I added garam masala and pepper. I was cooking ad lib, adding a little of this and that without taking notes… Which is annoying, because it turned out very nice! It had a remarkable aftertaste which gave me a somewhat dry feeling on the back of the tongue and it reminded me of mangoes. Even immediately after the meal I wasn’t able to recall all the ingredients.

As an undergraduate student I took an organic chemistry lab course, and I remember we were told not to use post it notes or small pieces of paper for taking notes. Everything should be recorded in a proper journal or - if necessary - small note books. Having finished my Ph.D. a couple of years later, I can only testify to this. Everything you do - be it in the lab or in the kitchen - should be recorded immediately in a journal. It’s amazing how something that was obvious one day, slips your mind a week or month later.

There is a wonderful Donald Duck story by Volker Reiche entitled “The soul of science” (the original appeared in 1981 in the Dutch Donald Duck magazine). At a point “Professor Duck”, who actually works as a janitor in a lab, utters the words “Careful notes are the soul of science” as he is caught experimenting. This is true also for the kitchen and experimental cooking. A German translation of the story was reprinted in the article “Das Leiden des cand. chem. Donald Duck” (open access) in case you want to read the whole story.

Careful notes are also the soul of kitchen science!

When taking notes it’s essential that you are able to re-cook the dish yourself. But if no one else is, the notes are of limited value. The biggest source of uncertainty in the kitchen is the widespread use of volume for measuring powders. This can best be illustrated by the question: How much does a cup of flour weigh?

I bumped into this when I began baking no-knead bread (recipe). I converted the recipe to metric units using an online calculator, but the no-knead bread wasn’t a huge success. The problem was that there is no simple answer to the question “How much does a cup of flour weigh?”. Cooking conversion online states that a cup of all-purpose flour weighs 99 g. King Arthur Mills claim that all their flours weigh 113 g/cup. USDA states 125 g/cup and Gold Medal 130 g/cup. Some cookbooks have settled at 140 g/cup (apparently because this is about half way between a loosely and densly packed cup) and if the flour is hard packed you can reach 160 g/cup. In other words - when following a recipe you would need to know how the volume of flour was measured in order to use exactly the same amount of flour. Some recipes call for “spoon and level” or “scoop and level”, but many do not include any information about this.

My recommendation is to weigh all dry ingredients (and preferably also the wet ingredients). A normal digital kitchen scale typically has a resolution of 1 g with an accuracy of +/- 5 g and they are quite affordable. Weighing liquids is also far more accurate than the average volume measurement in the kitchen. If the scale has a “tara” function it’s also much faster as you can zero the display after each ingredient you add. It shouldn’t come as a surprise that I’m not the only chemist advocating weight measurements in kitchen. And it’s not difficult finding other sites in favor of weight measurements either.

It therefore puzzles me why recipes that call for the following are still so abundant:

1 pack of instant yeast
1 envelope unflavored gelatin
1 gelatin sheet (see comment #4-5)
1 sachet powdered pectin
1 tablespoon liquid pectin
1 stick of butter
… and the list goes on

The only exception to the general advice on weighing ingredients is when very small quantities are used. This could be spices, food coloring or hydrocolloids. With normal kitchen scales, you’ll be better of using volume measurements for amounts less than 5 g (equal to a teaspoon if measuring water). Otherweise it’s worthwhile mentioning that scales with a 0.1 g and 0.01 g readout are getting cheaper and cheaper.

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There is a summary of the “10 tips for practical molecular gastronomy” posts. The collection of books (favorite, molecular gastronomy, aroma/taste, reference/technique, food chemistry) and links (people/chefs/blogs, webresources, institutions, articles and audio/video) at khymos.org might also be of interest.

Texture - A hydrocolloid recipe collection
It’s a pleasure for me to announce that an updated version of the hydrocolloid recipe collection is available for free download as a pdf file (73 pages, 1.8 Mb).

What’s new?
Several new recipes have been added (now counting more than 220 in total), including recipes with cornstarch, guar gum, gum arabic, konjac and locust bean gum. All in all 14 different hydrocolloids are included (plus lecithin which technically isn’t a hydrocolloid). In each section recipes are now sorted according to the amount of hydrocolloid used. The appendix has been updated with tables for comparison of hydrocolloid properties, hydrocolloid densities and synergies. The perhaps biggest change is that all recipes have been indexed according both to the texture/appearance of the resulting dish and according to the hydrocolloid used. Let’s say you want to make spheres, this index will show you which hydrocolloids can be used (that’s right - there are other possiblities than sodium alginate) and list the example recipes.

Foreword
A hydrocolloid can simply be defined as a substance that forms a gel in contact with water. Such substances include both polysaccharides and proteins which are capable of one or more of the following: thickening and gelling aqueous solutions, stabilizing foams, emulsions and dispersions and preventing crystallization of saturated water or sugar solutions.

In the recent years there has been a tremendous interest in molecular gastronomy. Part of this interest has been directed towards the “new” hydrocolloids. The term “new” includes hydrocolloids such as gellan and xanthan which are a result of relatively recent research, but also hydrocolloids such as agar which has been unknown in western cooking, but used in Asia for decades. One fortunate consequence of the increased interest in molecular gastronomy and hydrocolloids is that hydrocolloids that were previously only available to the food industry have become available in small quantities at a reasonable price. A less fortunate consequence however is that many have come to regard molecular gastronomy as synonymous with the use of hydrocolloids to prepare foams and spheres. I should therefore emphasize that molecular gastronomy is not limited to the use of hydrocolloids and that it is not the intention of this collection of recipes to define molecular gastronomy.

Along with the increased interest in hydrocolloids for texture modification there is a growing scepticism to using “chemicals” in the kitchen. Many have come to view hydrocolloids as unnatural and even unhealthy ingredients. It should therefore be stressed that the hydrocolloids described in this collection are all of biological origin. All have been purified, some have been processed, but nevertheless the raw material used is of either marine, plant, animal or microbial origin. Furthermore hydrocolloids can contribute significantly to the public health as they allow the reduction of fat and/or sugar content without loosing the desired mouth feel. The hydrocolloids themselves have a low calorific value and are generally used at very low concentrations.

One major challenge (at least for an amateur cook) is to find recipes and directions to utilize the “new” hydrocolloids. When purchasing hydrocolloids, typically only a few recipes are included. Personally I like to browse several recipes to get an idea of the different possibilities when cooking. Therefore I have collected a number of recipes which utilize hydrocolloids ranging from agar to xanthan. In addition to these some recipes with lecithin (not technically a hydrocolloid) have been included. Recipes for foams that do not call for addition of hydrocolloids have also been included for completeness. Some cornstarch recipes have been included to illustrate it’s properties at different consentrations. Recipes where flour is the only hydrocolloid do not fall within the scope of this collection as these are sufficiently covered by other cook books.

All recipes have been changed to SI units which are the ones preferred by the scientific community (and hopefully soon by the cooks as well). In doing so there is always uncertainty related to the conversion of volume to weight, especially powders. As far as possible, brand names have been replaced by generic names. Almost all recipes have been edited and some have been shortened significantly. To allow easy comparison of recipes the amount of hydrocolloid used is also shown as mass percentages and the recipes are ranked in an ascending order. In some recipes, obvious mistakes have been corrected. But unfortunately, the recipes have not been tested, so there is no guarantee that they actually work as intended and that the directions are complete, accurate and correct. It appears as if some of the recipes are not optimized with regard to proper dispersion and hydration of the hydrocolloids which again will influence the amount of hydrocolloid used. It is therefore advisable to always consult other similar recipes or the table with the hydrocolloid properties. The recipes have been collected from various printed and electronic sources and every attempt has been made to give the source of the recipes.

Since recipes can neither be patented nor copyrighted, every reader should feel free to download, print, use, modify, and further develop the recipes contained in this compilation. The latest version will be available for download from the static Khymos site and will also be announced here. I would like to thank readers for giving me feedback and suggestions on how to improve the collection. Feedback, comments, corrections and new recipes are always welcome at webmaster (a t) khymos ( dot ) org.

I recently blogged about the Alinea cookbook, and then in a Q&A with both Grant Achatz and Heston Blumenthal I discovered that there is another great cook book coming up this fall: The Big Fat Duck Cookbook! It’s quite amazing that these two books will be released within weeks of each other this fall.

This is what the publisher promises us:

In the first section of The Big Fat Duck Cookbook, we learn the history of the restaurant, from its humble beginnings to its third Michelin star (the day Heston received the news of this he had been wondering how exactly he would be able to pay his staff that month). Next we meet 50 of his signature recipes – sardine on toast sorbet, salmon poached with liquorice, hot and iced tea, chocolate wine – which, while challenging for anyone not equipped with ice baths, dehydrators, vacuum pumps and nitrogen on tap, will inspire home cooks and chefs alike. Finally, we hear from the experts whose scientific know-how has contributed to Heston’s topsy-turvy world, on subjects as diverse as synaesthesia, creaminess and flavour expectation.

With an introduction by Harold McGee, incredible colour photographs throughout, illustrations by Dave McKean, multiple ribbons, real cloth binding and a gorgeous slip case, The Big Fat Duck Cookbook is not only the nearest thing to an autobiography from the world’s most fascinating chef, but also a stunning, colourful and joyous work of art.

Compared to the Alinea cookbook this one is one is more expensive and has fewer recipes. But hey - who buys cookbooks based on the price/recipe anyway?