A good place to get started with molecular cooking is by using foams. Many foams are easy to make and they add great flavor and texture to a dish. They can also be applied easily to many of your favorite meals. Here we will show you how to make a soy foam adapted from the excellent Alinea cookbook.
Soy lecithin foams can be made from many liquids by adding between 0.2% and 1.0% soy lecithin by total weight to the liquid, heating it to a simmer, letting it cool, then blending it until it foams.
To make the soy foam we take equal parts soy sauce and water and whisk together with sugar and soy lecithin on the stove until it comes to a simmer. Strain it out and let it cool. Once you're ready to use it you just use an immersion blender on the liquid until it establishes a strong foam, about 2 to 3 minutes. You can then spoon the foam over your dish to serve.
If you like this recipe you can get more than 80 other recipes from my book Modernist Cooking Made Easy: Getting Started. The book covers many of the popular modernist techniques such as gelling, spherification, and foams. It also explores modernist ingredients like agar, sodium alginate, tapioca maltodextrin, and xanthan gum. It is all presented in an easy to understand format and I think it's the best way to learn about modernist cooking.\
Also, if you are just getting started experimenting with molecular gastronomy and modernist cuisine then I highly recommend one of these molecular gastronomy kits. They have everything you need to do many different dishes.
Combine all of the ingredients in a sauce pan. Bring to a simmer while whisking occasionally to break up any lumps. Strain through a chinois into a wide, flat bottomed, container. You can set the soy sauce mixture aside like this for several hours.When ready to serve, blend the soy sauce mixture using an immersion blender until a nice head of foam develops. Let the soy foam sit for 1 minute to stabilize and then spoon it out onto your dish.