Regardless of how you feel about the rise of mainstream diet trends, kale may be here to stay. From hip, urban cafes to the sprawling aisles of your local Costco, you’d be hard-pressed to find a thriving restaurant or grocer that doesn’t sell the tough, leafy green. Yet you might have an equally hard time successfully replicating the almighty kale salad at home.
The roughage can be tasteless if not bitter, and what’s the point of eating your veggies if you have to douse them in fatty dressing to make them palatable? These are exactly the types of issues that Dan Souza and Molly Birnbaum wanted to solve when they set out to write Cook’s Science—Cook’s Illustrated’s super-nerdy guide to navigating a home cook’s most vexing questions.
Both Souza and Birnbaum are editors and chefs at America’s Test Kitchen. “We use the scientific method in our recipe development in order to figure out the best methods for making our favorite dishes,” says Souza. One of those methods includes man-handling kale leaves in order to soften their texture, a tip kale enthusiasts describe as massaging the kale. The enthusiasts aren’t wrong—massaging kale does help wilt and soften the leaves, but it’s also partially to blame for kale’s bitterness. That’s because crushing the leaves breaks down the cell walls of two important chemicals naturally present in kale—the myrosinase enzyme and glucosinolates. When those walls deteriorate, the two chemicals interact and create a new, bitter compound that’s biologically designed to fend off hungry enemies. Despite its bitterness, kale has a ton of nutrients like Vitamins A and C, a host of antioxidants, and a mouthful of flavonoids. So luckily, that bitter compound washes right off the surface of the leaves. While common sense tells you to wash your veggies before you start chopping, you can actually get rid of the bitterness by working backward: massage, chop, then wash.
The idea behind Cook’s Science was to bring that kind of chemistry-filled expert advice to the Cook’s Illustrated fan base. Each of the book’s 50 chapters are dedicated to a different ingredient, including everything from ginger to pork to almonds and, yes, kale. So if you’re not satisfied with merely crushing your own kale, you can also learn the best conditions under which to grow the sweetest kale, or read how to pop out crunchy batches of kale chips using your microwave.
The ingredients featured in the book are ones that Cook’s Illustrated has been writing about in its magazines and books for years, but the focus has always been on how to cook something rather than the science of why you should cook it that way. In lieu of the grueling trial and error of recipe testing, the magazine had its famous hand-rendered drawings. But the nerdier side of cooking seems to have gathered more steam online, especially in recent years, so Souza and Birnbaum saw an opportunity to lift the curtain on the chemistry and physics behind their hard-won favorite recipes. “At the end of the day we feel that understanding some of the science behind cooking makes you a stronger, more flexible cook,” says Souza.
Take, for example, the magic of adding certain emulsifiers to your salad dressing in order to keep it from separating too quickly. You may have known that mayonnaise was a popular base for salad dressing, but you may not have known the reason—its rich in an emulsifier called lecithin, which holds water and oil together. When you understand the science behind ingredients like that, you can exploit it to make a dressing that stays together longer by adding more emulsifiers, like Souza suggests doing with his kale salad vinaigrette. That dollop of molasses he’s throwing in? It gets its rich, dark color and slow, lazy texture from a host of melanoidins—big, slow molecules that form when sugars and amino acids are condensed. Patiently drizzle it into your dressing and you have one powerful emulsifier that slows down the movement of the other liquids in the mix.
We brought Souza into WIRED to demo some of the book’s most helpful tips and explain how you can turn something as ubiquitous and boring as a kale salad into a savory, crunchy wonder. If kale isn’t your thing, do not despair. We’ll be releasing a series of these videos featuring Souza and his science-based cooking hacks over the coming weeks, so you can get a sneak peak into Cook’s Science while you’re fretting over what and how to cook for Thanksgiving.