From their website:

"Welcome to our Cookbook Collection

Millions of cooks know and love the test kitchen for our award-winning cookbooks. Our Cookbook Collection gives digital members exclusive online access to 2,000+ (and counting!) of these recipes.

America's Test Kitchen is a very real kitchen located in the Seaport neighborhood of Boston. It is the home of Cook’s Illustrated magazine and Cook’s Country magazine and is the Monday-through-Friday destination for more than four dozen test cooks, editors, food scientists, tasters, and cookware specialists. Our mission is to test recipes over and over again until we understand how and why they work and until we arrive at the “best” version.

We start the process of testing a recipe with a complete lack of conviction, which means that we accept no claim, no theory, no technique, and no recipe at face value. We simply assemble as many variations as possible, test a half-dozen of the most promising, and taste the results blind. We then construct our own hybrid recipe and continue to test it, varying ingredients, techniques, and cooking times until we reach a consensus. The result, we hope, is the best version of a particular recipe, but we realize that only you can be the final judge of our success (or failure). As we like to say in the test kitchen, “We make the mistakes, so you don’t have to.”

All of this would not be possible without a belief that good cooking, much like good music, is indeed based on a foundation of objective technique. Some people like spicy foods and others don’t, but there is a right way to sauté, there is a best way to cook a pot roast, and there are measurable scientific principles involved in producing perfectly beaten, stable egg whites. This is our ultimate goal: to investigate the fundamental principles of cooking so that you become a better cook. It is as simple as that."