On June 24, 2008, version 2.1 of the hydrocolloid recipe collection edited by Martin Lersch was released. This excellent collection is a useful (and free!) resource for those of us interested in molecular gastronomy. See below for download links for the PDF of the current version as well as the previous two versions. A PDF reader is required to view or print this document. (Please see the note below about printing.)
Lersch describes this new version, excerpted from his blog post:
This new 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.
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 donâ€™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 â€œresizeâ€ or â€œfit to paperâ€ option in your pdf reader.
Lersch, from the Forward of the new edition:
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 â€œnewâ€ hydrocolloids. The term â€œnewâ€ 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 â€œnewâ€ 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 this page and will also be announced on Khymos blog. 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 to webmaster atÂ khymos dot org.