members of the board finally prove that Hans’s so-called abilities were fake? They designed a series of scientific experiments. The simplest involved blindfolding the horse or having the trainer ask his questions out of Hans’s line of sight. As expected, suddenly his amazing intellect disappeared. The most interesting tests of all involved having the trainer ask the horse questions the trainer himself did not know the answers to. Guess what? If the trainer didn’t know the answer, neither did Hans.
THE POINT
here, of course, is that designing a successful experiment—whether it involves a mathematical horse or takes place in your own kitchen—is about eliminating the bias of the experimenter (in this case, you). This isn’t always easy to do, but it’s almost always possible.Let me tell you about an experiment I carried out a little while back to illustrate the seven key steps to a good tasting in the kitchen: eliminate bias, introduce a control, isolate variables, stay organized, address palate fatigue, taste, and analyze.
IS NEW YORK PIZZA REALLY
some say borders on the, well, the obsessive. The first time I heard that the mineral content of water might have an effect on the properties of bread dough was about ten years ago, when I read Jeffrey Steingarten’s gloriously obsessive piece about Roman breads in the chapter titled “Flat Out” in his book It Must Have Been Something I Ate:
In the shower, the shampoo refuses to lather. This means that Roman water is high in minerals, which can be good for the color and texture of bread, but slows fermentation and tightens the dough. I reach for my scuba diver’s underwater writing slate, as seen on Baywatch, indispensable for recording those flashes of insight that so often strike one in the bath. We must test the water of Rome.
Unfortunately, despite the heroic efforts he went through to bring true pizza bianca and pane Genzano to the home cook, the water issue was never satisfactorily resolved.
Well, eight years later, I decided to try to resolve it for myself, along with the help of another obsessive: Mathieu Palombino, chef-owner of New York City’s Motorino, who kindly volunteered to aid me in my little experiment. The idea is simple: the minerals dissolved in water (mostly magnesium and calcium) can help proteins in the flour bond together more tightly, forming a stronger gluten structure, the network of interconnected proteins that gives dough its strength and elasticity. So, the higher the mineral content of water (measured in parts per million, or ppm), the stronger and chewier the dough. In theory, it makes sense, and it is
easily provable in a laboratory. The more interesting question to me was, are the effects of the minerals in the water (referred to as Total Dissolved Solids, or TDS) significant enough to be detected by a normal eater in a real-world situation?
To answer the question, I charged Mathieu with making Neapolitan pizzas using waters with different TDS contents and brought in a panel of pizza experts to taste the finished pies. The problem is that the real world is, well, real, and as such, very difficult to control. In any scientific endeavor, there are a number of key principles that must be adhered to if you want to ensure that your results are accurate and repeatable—the hallmark of any sound experiment.
Key to a Good Tasting #1: Eliminate Bias
Despite our best efforts, we have yet to invent a device that empirically measures precisely how delicious pizza crust is, so our best option is to resort to the crude analyses of our mouths. Humans are notoriously bad at separating emotional responses to foods and food brands from their actual eating qualities, and the only way to eliminate this bias is with a double-blind tasting—a tasting in which neither the tasters nor the people preparing and serving the food know which sample is which.
To do that, I first gathered my waters—five different varieties of bottled waters with TDS contents ranging from less than 10 ppm (the maximum allowable for “purified”
waters) all the way up to 370 ppm (mineral water on the high end of the TDS scale), along with tap water. I chose the specific brands because they were available at my local
grocery.
• Aquafina: less than 10 ppm
• Dasani: approximately 40 ppm
• Tap water: approximately 60 ppm
• Rochetta: 177 ppm
• San Benedetto: 252 ppm
• Evian: 370 ppm
I transferred all the waters to clean bottles marked simply with numbers, making sure to note which water was in each bottle. That way, when I dropped the bottles off at Motorino
—which I did without actually seeing Mathieu, lest I unknowingly reveal any information, like Hans and his trainer—Mathieu would have no idea what he was working with.
Normally I systematically ignore the advice of my better half, a PhD student in cryptography (that’s the study of encryption, not the study of tombs), but this time, I shut up and listened to her for a change. She suggested that in order to further decrease bias and, more importantly, to allow me to participate in the tasting as well, she—an unbiased third party—should rearrange the numbered caps on all the bottles, taking note of which caps were moved to which bottles.
The result: three levels of encryption involving three different keys, none of which were useful on their own.
Neither myself, my wife, my tasters, nor our talented chef would know which pizza was made with which water until after the tasting, when my wife would reveal how the bottle
caps were switched, Mathieu would reveal which bottle of water was used to make each dough, and I would reveal which number corresponded to which brand.
Key to a Good Tasting #2: Introduce a Control
The concept of a control is a simple one, but one that is often overlooked. The idea is that you need to include at least one sample in your tasting for which the answer is already known. That way, you can be sure that the experiment went according to plan and that your other results are reliable. In the case of a double-blind experiment like this one, it means doubling up on at least one of your samples. If the results for both are the same, then you have a pretty strong case that the experiment went according to plan.
In this case, I doubled up on both tap water and Evian, making a total of eight water samples. If the testing procedures were sound, and our palates were as fine-tuned as I believed them to be, the crusts made with the same water should be ranked very close to each other in the tasting.
Key to a Good Tasting #3: Know What You Are Asking (Isolate Variables)
In Douglas Adams’s Hitchhiker’s Guide to the Galaxy, a team of scientists builds a supercomputer that is finally able to answer the Big Question: the Answer to Life, the Universe, and Everything. The ultimate irony is that when they’re finally given the answer—forty-two—they realize that they never really knew exactly what they were asking in
the first place.
Now, these were very poor scientists. Rule Numero Uno when it comes to science is this: Be very precise about what question you are trying to answer. The more limited the scope of your question, the easier it will be to design an experiment to answer it. There are approximately a gajillion variables when it comes to pizza, each one of them interesting in its own way. But here, I was interested in only one: how does the water’s mineral content affect the dough?
What that meant was that in order to isolate that single variable, I’d have to ensure that every single other variable out of those gajillion remained exactly the same from sample to sample. Easier said than done.
In the real world—particularly with cooking—there are an insane amount of variables to try and control for. Perhaps that log in the wood-burning oven is gonna burn slightly hotter for pizza #2 than for pizza #1, raising the temperature by a couple of degrees. Or maybe Mathieu will have to wait for a server with a load of dishes to pass by before inserting pizza #5 into the oven, adding a few seconds to its trip. This is an inevitable, unavoidable reality when it comes to science. What we can hope, however, is that these tiny changes in method from sample to sample will make a negligible difference compared to the variable we are actually testing for. We can also do our best to make sure every sample is treated the same.
I asked Mathieu to weigh the ingredients for each batch of dough precisely and to ensure that each batch was kneaded for the same length of time and allowed to ferment at the same temperature. While normally the pizzaioli at the
restaurant take turns shaping, saucing, and baking the pizzas, this time Mathieu himself made each one from start to finish, ensuring that the method used was as consistent as possible.
On top of those measures, I also decided to present each sample in two forms: as a completed Margherita pizza and as a simple disk of dough baked on its own, to eliminate any variability that differences in topping distribution might add.
Key to a Good Tasting #4: Stay Organized
Who better to taste pizzas than New York’s foremost pizza cognoscenti, Ed Levine and Adam Kuban? In addition, Alaina Browne of the Serious Eats team joined us, along with my wife (as a reward for her good advice), and—
through a miraculously fateful act of good networking—
Jeffrey Steingarten himself, the very man who had unknowingly started me down the path of pizza (and, indeed, of food writing, period). Before arriving at the restaurant, I drew up tasting sheets for my panel to fill out.
Each pizza was to be evaluated in four categories, and each category was rated on a scale from one to ten:
• Dough Toughness: Is it tender like cake or as chewy as leather?
• Dough Crispness: Does it crackle, or is it flaccid?
• Oven Spring: Did it form large, airy bubbles, or is it compact and dense?
• Overall Quality: How do you like it?
The first five tasters (including myself) arrived promptly
at 4 p.m., with chef Mathieu waiting for us. Jeffrey, however, was nowhere to be seen, though he had warned me that he might be a bit late due to an important meeting.
Ed phoned up his assistant. Evidently, his important meeting was in his bed with Sky King, his dog, but not to worry—his jacket was on, and he was hard at work on his shoelaces.
Meanwhile, Mathieu informed us that he’d dropped half of the first sample on the floor, meaning that for that batch, we’d only be tasting one pie, not two. Not to worry. Even Tesla must have dropped a few coils in his day, right? My perfectly orchestrated plans were beginning to slip, but a glass of Brachetto and a small plate of fingerling potatoes tossed with anchovies and olives helped me pull my senses back into focus.
Key to a Good Tasting #5: Watch Out for Palate Fatigue As soon as Mr. Steingarten arrived, fresh from his nap, I turned to Mathieu and gave him the go-ahead. Within three minutes, the first leopard-spotted, tender-crisp beauty was on the table. Eight pizzas among six people is a lot to consume in a single sitting, even for epic eaters like our humble tasting panel, and there was no way the pizzas in the latter half of the tasting were going to get a fair shake.
Ideally, we’d have each taster taste samples in a different order. That way, one would be starting with number one, another with number six, another with number three, and so on, hopefully evening out the playing field. But given that the pizzas had to be baked one at a time, this was simply not possible. So we did the next best thing: one pie out of each batch of two was eaten straight out of the oven and the
second one was saved until all eight were on the table. That way, we could go back and retaste to ensure that our original thoughts were sound, and we could taste all eight side by side.
Sparkling water and wine were provided (the latter after much deliberation) in order to rinse our mouths between bites.
Key to a Good Tasting #6: Taste
Tasting is different from eating. I often get asked, “How can you review a restaurant fairly or how can you say one product is better than another? Doesn’t it depend on how hungry you are at the time?” And, indeed, mood and appetite can have a powerful effect on how much you enjoy eating a particular food at any one time. But the goal of analytical tasting is to assess qualities of the food beyond your gut reaction of whether it’s good or bad. With pizza, for example, I start by taking a slice from each pie with an across-pie-average of charring, bubbles, sauce, and cheese.
I then bite just the tip, noting the pressure of the crust on my lower teeth to gauge its degree of crispness. As I pull the slice away from my mouth, applying just a bare soupçon of torque, I judge the effort it takes for the dough to tear. (In this case, Pizza #5 was clearly tougher than the rest, I thought triumphantly—one must never talk to his fellow tasters during a blind tasting lest your opinion influence those of others—so it must certainly be one of those high-mineral samples.)
After carefully working my way up the side of each slice, I evaluate the cornicione (the raised rim of the pizza). It’s
hard to find fault with any of them, but does #3 look just a shade paler than the rest, indicating a lower-mineral-content water? Could be. But if so, why isn’t it also more tender?
See, these are observations you can make relatively empirically—that is, free from bias. Sure, eating the same pizza when starving versus when stuffed will elicit two different reactions, but by reducing each one to basic elements that are more easily quantified—crispness, chewiness, degree of charring—you can get a more accurate picture of the pizza overall, divorcing it from the mental bias of your current state of mind.
With the pizzas tasted, we thanked Mathieu for his incredible pizza (the best in the city, for my money), and bravely made our separate ways through the night, several degrees more content and several pounds heavier.
Key to a Good Tasting #7: Analyze
Once all the tasting has been done and all the data collected, it’s your job to analyze it in order to make the most reasonable assessment you can about what factors are affecting your variable. In the case of the pizzas, that meant charting the data and listing it in order from lowest mineral content (which should presumably deliver more more tender, softer, less-sprung, paler dough) to highest. If everything went according to theory, the lines for crispness, toughness, and airiness should all show distinct trends, going up or down as the mineral content of the water increases.
As it turns out, no such trends existed. True, the two batches made with Evian—the highest mineral content of all
the water we tried—delivered the crispest crusts, but overall, there was not enough of a trend in the data to make a definitive statement. And you know what? Sometimes—
more often than not—an experiment, no matter how closely controlled, does not produce the results you were looking for. Which is not to say that we got no results at all. In fact, taking a second look at the data, I saw that the rankings for crispness follow in step pretty closely with the rankings for overall enjoyment—implying that our enjoyment of pizza is directly related to how crisp it is. We all want a crisp crust, not a soggy one.
Earth-shattering, I know.
On the other hand, we can now pretty definitively say that the small differences that arise naturally in the course of making a good pizza by hand far outweigh any difference the mineral content of the water could make. That is to say, great New York pizza is most certainly not dependent on using New York City tap water, which is good news for everyone else in the world.
{ What is cooking? }
I
know you’re eager to jump right in and start cooking, but first answer this question: What is cooking?If you’re my wife, your answer will be, “It’s that thing you do when that crazy look comes into your eyes.” A great chef might tell you that cooking is life. My mom would probably say that it’s a chore, while my wife’s aunt would tell you that cooking is culture, family, tradition, and love.
And, yes, cooking is all of those things, but here’s a more technical way to think about it: Cooking is about transferring energy. It’s about applying heat to change the structure of molecules. It’s about encouraging chemical reactions to alter flavors and textures. It’s about making delicious things happen with science. And before we can even begin to understand what happens when we grill a hamburger, or even what equipment we might want to stock our kitchen with, we have to get one very important concept into our heads first, as it’ll affect everything we do in the kitchen, starting with which pots and pans we use. It’s this:
Heat and temperature are not the same thing.
At its most basic, cooking is the transfer of energy from a heat source to your food. That energy causes physical changes in the shape of proteins, fats, and carbohydrates, as well as hastens the rate at which chemical reactions take place. What’s interesting is that most of the time, these
physical and chemical changes are permanent. Once a protein’s shape has been changed by adding energy to it, you can’t change it back by subsequently removing that energy. In other words, you can’t uncook a steak.
The distinction between heat and temperature can be one of the most confusing things in the kitchen, but grasping the concept is essential to helping you become a more rational cook. Through experience, we know that temperature is an odd measure. I mean, pretty much all of us have walked around comfortably in shorts in 60-degree weather but have felt the ridiculous chill of jumping into a 60-degree lake, right? Why does one but not the other make us cold, even though the temperature is the same? Let me try to explain.
Heat is energy. Third-grade physics tells us that everything from the air around us to the metal on the sides of an oven is composed of molecules: teeny-tiny things that are rapidly vibrating or, in the case of liquids and gases, rapidly bouncing around in a random manner. The more energy is added to a particular system of molecules, the more rapidly they vibrate or bounce, and the more quickly they transfer this movement to anything they are touching—
whether it’s the vibrating molecules in a metal pan transferring energy to a juicy rib-eye steak sizzling away or the bouncing molecules of air inside an oven transferring energy to the crusty loaf of bread that’s baking.
Heat can be transferred from one system to another, usually from the more energetic (hotter) system to the less energetic (cooler). So when you place a steak in a hot pan to cook it, what you are really doing is transferring energy from the pan-burner system to the steak system. Some of