What do you get when you turn a biochemist loose in the kitchen of a school for boys? You get Shirley Corriher, a gift to anyone interested in food and cooking. Her book, KitchenWise, arrived unsolicited in the mail as an early Christmas gift. What a delightful book from a delightful person!
Many years ago I was at a dinner meeting of Dixie (since renamed Southeast) IFT looking for a vacant table. At banquets I pick out a table with people I don’t know to gain perspective and knowledge. That night my wife and I hit the jackpot. We landed a seat by Shirley and her husband Arch.
In the interest of full disclosure, Shirley is a friend of mine. We exchanged our most recent books, including KitchenWise. I am mentioned in the book a few times—given more credit than I deserve. There is no way I can be objective in this review. But, if you cook at home or love food science, I suspect that you will like this book. I did. It is short and chock full of useful nuggets.
Below I react to Shirley’s words of wisdom in bold:
“When you heat many natural proteins, or expose them to acids, salts, or even to air, the bonds holding them together break down. The springs and coils pop open and unwind. The unwound protein (called denatured protein, because it has changed from its natural form) is now floating about with its bonds sticking out.” (p. 23-24) Heating sets off a molecular extravaganza of change in a food. One of the myriads of changes that occur involves the unfolding of proteins. These reactions form delicate flavors and exquisite textures. Lazy cooks rely on pregelatinized (denaturation) Quick Grits and Oatmeal.
Shirley’s descriptions of proteins transport me back to technical books and courses. Whitaker’s Principles of Enzymology for the Food Sciences comes to mind. They also trigger memories of Brandts “Physical Chemistry of Proteins.” What a dastardly course! Visions of amino acid chains start dancing in my head. I hope I don’t have nightmares tonight! Links between food science and cooking inform each other throughout the book. As I tell my wife, cooking is all about time-temperature relationships. Shirley reveals many cooking secrets between the book’s covers. Experienced cooks can learn the science behind their methods. Food scientists can learn how the basic principles they know apply to life in the kitchen.
“Potatoes can become gluey if you break a lot of the starch granules in mashing. If you mash potatoes in a food processor, you really shear the starch granules and will get a gluey mess—wallpaper paste.” (p. 142) I had not tasted mashed potatoes since childhood. Growing up in the Midwest, I had potatoes as part of almost every meal. The only rice we ever ate was in rice pudding! Nostalgia took over, and I had to make some for my wife and me. It turns out that many factors affect preparation of the prefect mashed potatoes. It starts with choosing the right kind of potato. Well, it couldn’t be as hard as Shirley indicated. I cut a corner or two. OK, more than two. I avoided wallpaper paste, but I ended up with a less than gustatory sensation. It is important to treat starch crystals with the respect that they deserve.
“Chemical emulsifiers are natural or man-made molecules that have one end that dissolves in oil and another end that dissolves in water. Egg yolks contain phospholipids, lecithin, and many other molecules that are emulsifiers.” (p. 168) Emulsifiers stand between the cook and a successful sauce or dish. Almost anyone can heat and mix. The creative cook brings together disparate ingredients to produce meals that delight. Emulsifiers provide creaminess and thickening. KitchenWise is full of tricks to stabilize emulsions. When I taught “Food Chemistry” I harped on the importance of functional properties. Each ingredient performs at least one critical function. Functional properties of ingredients result from their molecular composition and structure. Molecules from one ingredient interact with molecules from other ingredients. These reactions deliver the desired color, flavor, and texture. The proper sequence of ingredient addition is so important in finished quality. Egg yolks are a master ingredient with many functions.
“Wrap for frozen food must be both moisture- and vapor-proof. Many plastic wraps, wax paper, and even foil have tiny holes through which moisture and oxygen can pass.” (p. 171) Freezer burn is real. Frozen food is not inert unless it is stored at temperatures suitable for Pfizer vaccines. Water is active within a frozen food. It can migrate to the surface of the food and escape the bounds of ordinary packaging. Likewise, oxygen gains access to susceptible food molecules in inadequate packaging. Few things are as damaging to food quality as rogue oxygen. Left unattended for a few days or even weeks, food can resist water and oxygen migration. Left unattended for months, slow migration of these molecules inflicts major damage. Disappointing eating experiences are a consequence of inadequate packaging materials.
The most important function of packaging is containment. A food package does much more. A proper package keeps desirable odors in and undesirable odors out. It also controls portions while preventing insect and microbial invasion. Proper packaging reduces food waste. We hear about plastic waste and its threat to our environment. Few packaging materials function as well or are as versatile as plastic in our modern world. Therein lies the existential problem of plastics.
“The more extensible the gluten is, the more it can stretch, the more the loaf can rise. It may be that a wheat that forms more extensible gluten can make a loaf with as good or better rise than a higher protein wheat that makes more elastic gluten.” (p. 188) Gluten does not occur as a natural component in a wheat seed or even the dry flour. It takes human activity and an added ingredient, water, to produce gluten. Gluten is the combination of two proteins in the wheat, glutenin and gliadin. And, no, it did not appear like magic in the 1940s by advanced forms of wheat breeding.
Gluten is what allows wheat breads to be light and fluffy. Bakers want a high-gluten-producing flour for breads and a low-gluten-producing flour for cookies. During the baking process, yeasts or baking powder produce the gas carbon-dioxide. In bread baking the gluten stretches to form air pockets allowing the dough to rise. In cookies, we don’t want big air bubbles. Shirley describes how each ingredient plays a critical role in final quality of a cookie. No matter how tempting, do not cut corners when baking cookies.
“Cocoa butter has a sharp melting point, which is right at body temperature. You bite into hard, firm pieces of chocolate, then seconds later your mouth is filled with aromatic, luxurious, thick liquid and the sublime taste of real chocolate.” (p. 241) Speaking of magical ingredients, let’s talk about chocolate. The most important quality characteristic of chocolate is its melting properties. Baker’s (natural) chocolate is 55% fat, almost all saturated fat. The melting of the cocoa butter in the mouth releases its enticing flavors. I taught a Freshman Seminar in “Chocolate Science.” It became my signature tool in recruiting students into the Food Science major. It also netted me invitations to give guest lectures around campus and beyond. Each lecture featured edible aids.
Milk-chocolate M&Ms illustrate the principle of melting properties of ingredients. Participants put a few of these candies on their tongue. They wait for the chocolate fat to melt. What a sensuous feeling! Try this one out at home. Few foods are more pleasurable than a chocolate treat lingering on the tongue! Two ladies approached me after one of these lectures. The younger lady declared “My mother liked your lecture more than anyone else here.” I responded “And why was that?” “Because she has no teeth!” replied the daughter. The older woman opened her mouth. Nothing but gums!
Melting points are critical in sensations delivered by many fatty items. Think ice cream. The slow-melting properties of high-quality (high-fat) frozen desserts contribute to our pleasures. The frozen treat delivers a velvety texture that also lingers in the mouth. Low-fat products are not the same. Pull a package out of the freezer and it is as hard as a brick. Leave it out for a few minutes to thaw, and it turns to liquid. Cooks and manufacturers incorporate fats into their confection due to its functional properties.
“Whatever cooking method you choose, it’s important to keep perspective. When it’s time to start cooking, I think about food as more than just sustenance. For me, the decision of how to cook my vegetables includes things like flavor, appearance, time and which method my family prefers.” (p.98) How true! Cooking is about so much more than nutrition. This principle is what I refer to as on-the-plate nutrition versus in-the-stomach nutrition. It doesn’t matter how nutritious a meal is if it is not eaten and digested. Cooking and science are not about perfection. They are about experimenting, learning, adapting, and succeeding. Shirley also has a nice discussion of natural toxins. Not all natural foods are harmless. Not all processed foods are harmful. Too many writers exaggerate the dangers of processed foods. It is important to know which foods pose a danger and which ones do not.
“We in the United States are fortunate to have probably the most abundant and safest food supply in the world thanks to our agricultural and animal husbandry expertise and our food overseers like the USDA, the FDA, and the CDC.” (p. 257) Finally, it is great to see a tribute to the farmers and scientists who bring forth an abundant food supply. Also, the governmental agencies work with diligence to keep our food supply safe. We hear so much negative publicity about our government and our food supply. Most of us are fortunate to live in a country that provides us safe, wholesome food. Somehow, we need to work on ways to provide greater access to people who live in food deserts and swamps.
Bottom Line. I am pleased to recommend my friend’s book for your reading and cooking pleasure. Shirley lets us in on numerous tricks for the home cook—some of which even the veteran cooks may not have considered. She provides troubleshooting tips when a recipe goes wrong for whatever reason. As an added bonus, she teaches us some key scientific principles along the way. She also illustrates that the science behind cooking and processing is the same. It is how we use that science that makes the difference.
Next week: Sugar as an ingredient: functional and dangerous