Kitchen Mysteries

Kitchen Mysteries: Revealing the Science of Cooking

Hervé This
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    Kitchen Mysteries
    Book Description:

    An international celebrity and founder of molecular gastronomy, or the scientific investigation of culinary practice, Hervé This is known for his ground-breaking research into the chemistry and physics behind everyday cooking. His work is consulted widely by amateur cooks and professional chefs and has changed the way food is approached and prepared all over the world.

    In Kitchen Mysteries, Herve This offers a second helping of his world-renowned insight into the science of cooking, answering such fundamental questions as what causes vegetables to change color when cooked and how to keep a soufflé from falling. He illuminates abstract concepts with practical advice and concrete examples-for instance, how sautéing in butter chemically alters the molecules of mushrooms-so that cooks of every stripe can thoroughly comprehend the scientific principles of food.

    Kitchen Mysteries begins with a brief overview of molecular gastronomy and the importance of understanding the physiology of taste. A successful meal depends as much on a cook's skilled orchestration of taste, odors, colors, consistencies, and other sensations as on the delicate balance of ingredients. Hervé then dives into the main course, discussing the science behind many meals' basic components: eggs, milk, bread, sugar, fruit, yogurt, alcohol, and cheese, among other items. He also unravels the mystery of tenderizing enzymes and gelatins and the preparation of soups and stews, salads and sauces, sorbet, cakes, and pastries. Hervé explores the effects of boiling, steaming, braising, roasting, deep-frying, sautéing, grilling, salting, and microwaving, and devotes a chapter to kitchen utensils, recommending the best way to refurbish silverware and use copper.

    By sharing the empirical principles chefs have valued for generations, Hervé This adds another dimension to the suggestions of cookbook authors. He shows how to adapt recipes to available ingredients and how to modify proposed methods to the utensils at hand. His revelations make difficult recipes easier to attempt and allow for even more creativity and experimentation. Promising to answer your most compelling kitchen questions, Hervé This continues to make the complex science of food digestible to the cook.

    eISBN: 978-0-231-51203-9
    Subjects: General Science

Table of Contents

  1. Front Matter
    (pp. i-iv)
  2. Table of Contents
    (pp. v-vi)
  3. Series Editor’s Foreword
    (pp. vii-xii)
    Albert Sonnenfeld

    As an ever-curious if scientifically untrained food lover and sometime home sous-chef, I have long sought to grasp the rationale that science might offer to explain the not-infrequent disasters I have produced in my unscientific and amateurish cooking. Thanks to Hervé This, I discovered that I could live with the pitfalls as long as failure could become a learning experience.

    What makes microwave heat so different from gas-fired ovens that it causes a tarte Tatin to go all soggy? Why did that soufflé fail to rise, what diabolical chemistry caused my béarnaise to liquefy? Call Hervé This. He is our...

  4. Cooking and Science
    (pp. 1-10)

    “Add the cheese béchamel to the egg whites, beaten into stiff peaks, without collapsing them!” Such vague instructions in a soufflé recipe often make amateur cooks nervous. How to avoid collapsing those laboriously beaten egg whites? In our ignorance, we begin by using what we think is a gentle—that is, slow—technique. The egg whites and the béchamel do not mix easily, so we stop before we have a homogeneous blend or we stir the two ingredients so long that the egg whites collapse. In both cases, the effect is the same: the soufflé is ruined.

    Where does the...

  5. The New Physiology of Flavor
    (pp. 11-28)

    Before digging into the main course—the methods of preparation—let us make a little detour useful to understanding how we eat, because we will be better cooks if we know how to distinguish the various sensations that dishes produce: tastes and flavors, colors, scents, aromas.

    Aristotle knew everything, but what did he know about tastes? Let us entrust ourselves to this old philosopher. Tirelessly traversing the lyceum with his disciples, he worked up an appetite and turned his metaphysical mind toward gourmand meditations: there are “in the tastes as in the colors, on the one hand, the simple kinds...

  6. Soup
    (pp. 29-30)

    Those of you who love to eat know why cooking inspires enthusiasm. Do you know why science has its enthusiasts as well? Because it holds the key to a secret world, parallel to the one we all know but so different! Some, who pass for gentle dreamers among their more businesslike friends, have gotten lost there.

    What is this world made of? Atoms and molecules in constant motion. What do these molecules look like? That all depends on who imagines them and the framework in which they are placed. To the young chemist’s eyes, they are often groupings of colored...

  7. Milk
    (pp. 31-33)

    One of the major difficulties in science is accurately assessing situations. To what degree can one simplify a system without losing the essence of the phenomenon one wants to understand? To explain how soup is cooled, I compared it to water, because the heat exchanges on the surface, which are solely responsible for the cooling, are identical for soup and water. If we were interested in the properties of flow, only a very watery soup could be compared to water. Like the poet, the physicist and the chemist must be masters of metaphor.

    To understand why milk boils over, can...

  8. Gels, Jellies, Aspics
    (pp. 34-38)

    Gels, jellies, aspics . . . At these words, the gourmand is overcome with visions of brilliant dishes where the transparency of a glossy coating haloes immense fish surrounded by herbs or slivers of truffles adorning roast fowl. Beauty is not the only characteristic of aspics. In the mouth, they melt deliciously, leaving behind the quintessence of the flavors sealed within.

    The gourmand secret in these dishes is in the jelly, whose mysteries have now been revealed to us by physics, prompted by the photography industry.¹ After centuries of empiricism, today’s cooks are now equipped with knowledge of the reasons...

  9. Mayonnaise
    (pp. 39-43)

    You take a bowl, and you pour in oil, then water: two phases separate from each other, the water, which is denser, below; the oil, which is less dense, on top. You whisk it: a few drops of water enter the oil, a few drops of oil go into the water, but as soon as the agitation stops the oil droplets rise again and the water droplets descend. The two phases separate once more.

    What miracle allows the water in an egg yolk (about half the yolk and about 90 percent of the vinegar) and oil to remain mixed in...

  10. The Egg’s Incarnations
    (pp. 44-49)

    The egg is the unrecognized star of cooking. In his Almanach des gourmands, Grimod de la Reynière celebrated it in these terms: “The egg is to cooking as the articles are to speech, that is to say, such an indispensable necessity that the most skillful cook will renounce his art if he is forbidden to use them.”

    How true! Its whites, beaten into stiff peaks, merit their own chapter. Soufflés, which they cause to rise, require the examination of so many principles of physics that, again, a complete chapter will be necessary if we are to master them. And the...

  11. A Successful Soufflé?
    (pp. 50-57)

    How to succeed at soufflé every time? Some soufflé magicians tirelessly repeat the techniques that, one day, just out of luck, guaranteed them their success. I make no claims to helping them. But what about the rest of us, whose luck has not led us to the appropriate sleight of hand? We will obtain good results more reliably if we truly understand what a soufflé is and how its constituent parts react.

    A soufflé is always a foam of egg whites with some preparation added: an herbed béchamel sauce for savory soufflés or a mixture of milk or puréed fruit...

  12. Cooking
    (pp. 58-62)

    As mentioned earlier, in cooking we have three objectives: to kill harmful microorganisms that contaminate food, to change the consistency of foodstuffs, and to give them flavor. Often the cook achieves these ends simultaneously, because heat, which kills microorganisms, for example, also degrades meat’s toughest molecules and triggers chemical reactions that engender aromatic compounds.

    Why does cooking tenderize meat? Why does it make vegetables lose their rigidity? And, more generally, what is the secret of culinary transformations?

    The culinary arts begin and end with the art of cooking, and it certainly isn’t feasible to summarize the whole book in this...

  13. The Boiled and the Bouillon
    (pp. 63-68)

    For a long time, meat was believed to be made up of two parts: the part that passed into the bouillon when meat was cooked in water for a long time and the fibrous part, which was called le bouilli, or the boiled. Gourmands did not have words harsh enough for le bouilli. Stripped of its succulent elements, boiled meat no longer deserved a place on their tables.

    Brillat-Savarin relates the following anecdote in honor of the “osmazome,” which was supposed to be the principal component of taste in meats:

    The Prince of Soubise planned to give a great party...

  14. Steaming
    (pp. 69-70)

    Boiled meat can be tender, certainly, but it has no flavor. In the last chapter, we saw that the tough part, the connective tissue and especially the collagen, is dissociated as it reacts with the water, but the odorant and sapid molecules escape from the meat into the bouillon. All that remains are tasteless fibers.

    Can the flavor of the meat be retained even while it is tenderized? That is the principle behind cooking with steam, no different from cooking in a sealed pot (à l’étouffée), a long cooking process in an atmosphere saturated with water vapor. During this operation,...

  15. Braising
    (pp. 71-74)

    I would love to introduce you to the notion that the supreme cooking method is braising. In this transformative operation that takes place in a closed receptacle, with almost no liquid, the meat loses as few elements as possible. Instead of the elements of the meat escaping into the liquid, the meat absorbs the best of the liquid.

    Before going further, let us recall cooking’s old familiar refrain: to kill microorganisms, provide flavor, and make tender. In braising, these operations take place in two stages: cooking at a high temperature, which kills microorganisms, browns the meat’s surface, and creates odorant...

  16. Chicken Stew, Beef Stew, Veal Stew
    (pp. 75-76)

    When should salt be added to a beef stew, a veal stew, or one of those chicken stews of good King Henry?

    Try this if you have not already considered this question. One day when you have a little more time than usual at your disposal, make double the amount of a dish and experiment with the effect of salt. In two saucepans heated in identical fashion, place the same ingredients in equal quantities, but salt one of the dishes before cooking and the other one after. You will soon see the difference . . . and the importance of...

  17. Questions of Pressure
    (pp. 77-78)

    The pressure cooker is an antimountain. At higher altitudes, the air becomes rarified, and the air pressure is lower than that at sea level, so water molecules, for example, more easily escape the body of liquid in which they are found. In short, water boils at a temperature lower than 100°C (212°F). In a pressure cooker, the water that evaporates at the beginning of the cooking gradually increases the pressure in the pot, so water molecules have more difficulty escaping the liquid. The boiling point of the water is thus increased. In practice, today’s pressure cookers are devised so that...

  18. Roasting
    (pp. 79-84)

    A quick cooking process that is not meant to tenderize the meat, roasting is reserved for choice pieces that come from young, tender animals. It leaves the characteristic flavor of the meat intact, adding only a delicate touch on the surface. The juices, most of which remain in the flesh, flood the mouth with subtle flavors when one bites into the meat.

    A roast retains its succulence only when it is seared. The oven must be preheated, the meat must be coated with oil, which conducts heat better than water, and ideally steam must be eliminated. Without allowing too many...

  19. Deep-Frying
    (pp. 85-88)

    All cooks know that frying is cooking through contact with hot oil. They know that this operation creates a golden crust, but they distrust heated oil, which spatters, makes the kitchen greasy, and produces the taste and smell of burnt fat as it gradually darkens. And that is why some physicians condemn deep-frying on dietary grounds.

    The makers of household appliances have already overcome the first two inconveniences of deep-frying by inventing deep-fryers equipped with a filter and in which the operation takes place in a closed vat. Is there a way to overcome the last inconvenience, of reconciling the...

  20. Sautés and Grills
    (pp. 89-91)

    Strictly speaking, to sauté is to cook meat, fish, or vegetables in a fatty substance over high heat, uncovered, and without adding any liquid. In practice, however, for large pieces of food especially, this first phase of cooking must be followed by more gentle cooking, in an open pan, so that the odorant molecules in the vapor can add the finishing touches to the initial sauté. A true sauté differs from braising in that, with an uncovered pan, no vapor limits the cooking temperature. As with deep-frying, cooking takes place at a temperature higher than the 100°C (212°F) of boiling...

  21. Even More Tender
    (pp. 92-96)

    Very fresh meat is tender, but fresh meat is tough; gradually it becomes tender again, and then it rots. How to conserve it in that precarious state in which it does not require excessive chewing but neither does it release an unbearable odor, revealing an unhealthy degree of putrefaction? Our ancestors invented many processes for long-term conservation: smoking, salting, drying. But today’s cooks can get meat anytime at all from the neighborhood butcher, who sells cuts that are aged for exactly the right amount of time. They no longer have to solve the problems of long-term conservation. Beginning with products...

  22. Salting
    (pp. 97-98)

    Those nitrates that ecologists condemn for polluting streams and rivers are present in foods preserved with salt. Potassium nitrate, that is, saltpeter, has been used in this way empirically since the Middle Ages, even since Roman times. In 1891 the biologist H. Polenski demonstrated that bacteria transform saltpeter into nitrite in meat. Then in 1899 came the discovery that the characteristic color of salted products was due to these nitrites and not to the nitrates themselves. In 1901 the biologist John Scott Haldane found that this color resulted from the combination of the chemical group NO with the meat pigments....

  23. Microwaves
    (pp. 99-101)

    Cooked in a microwave, beef is rejected by taste testers, who find fault with its grayish external color, the uniformity of its internal color, its toughness, its lack of succulence, and its bland taste. And they are right. Microwaves penetrate into the mass of the foodstuff for several dozen millimeters before being absorbed by the water molecules. These molecules are heated, then vaporized. The temperature never goes above 100°C (212°F). Now, as we have seen, heating in this way is fatal to meat, which must be heated intensely to achieve the browning produced by Maillard and other similar reactions.


  24. Vegetables: COLOR AND FRESHNESS
    (pp. 102-109)

    Vegetables, the jewels of the kitchen! Did they not give their names to the great Roman families? Fabius, in honor of faba, or fève, the broad bean; Lentulus, in honor of the lentil; Piso, in honor of the pea; Cicero, in honor of the chickpea.

    Vegetables must be eaten fresh to be good. The soil in which they were cultivated, the climate that brought them to life will sing in one’s mouth . . . if they are not mangled in the cooking process. Cooking them is a delicate operation. How long must they cook to become sufficiently tender? Must...

    (pp. 110-125)

    Before they sang of Trojan heroes or the adventures of Ulysses, the Greek poets invoked the Muses, who were supposed to ensure the truth of their poetic madness. As modern bard of one of the basic components of cooking—the sauces—I invoke Ali-Bab, that early-twentieth-century French engineer who, upon returning from his numerous world travels, offered gourmands the fruits of his long travel experience. His Gastronomie pratique hardly merits its name, but his paragraph on sauces deserves to be quoted:

    Sauces are liquid food combinations, thickened or unthickened, that serve to accompany certain dishes.

    Thickened sauces, by far the...

  26. A Burning Question
    (pp. 126-127)

    Why do we like hot pepper, which burns? How can what is good be bad? Before turning to the pepper itself, let me enlarge on the question it poses for us: Is eating harmful?

    Brillat-Savarin devoted a few juicy pages to the excesses of dining. Remember, this is his second aphorism: “Animals feed themselves; men eat; but only wise men know the art of eating.”¹ And his tenth: “Men who stuff themselves and grow tipsy know neither how to eat nor how to drink.”²

    Very well. So eating or drinking too much is harmful. Today’s doctors even try to specify...

    (pp. 128-130)

    Salad, with the vinaigrette that accompanies it, is a dish that the gourmand has never managed to fall in love with completely. It is a delicate, refreshing, and welcome complement to a big meal, but it “kills” the wine because of its acidity. If you serve salad, give your guests only water to drink with it, and change mounts, as riders say, for the cheese and dessert courses. The salad interlude requires that a completely different wine follow the one you served with the meat.

    How should a salad be prepared? We all think we know how: you wash the...

  28. Yogurt and Cheese
    (pp. 131-133)

    I warned you in my introduction, my dear guest of gastronomical literature, that I would only lead you where your own cooking resources would suffice. So do not take me to task for offering too little advice when it comes to cheeses. These appear at the table in just the state in which they were acquired. At best, through a little elementary care, you might continue the maturing process accomplished by your cheese maker.

    Nevertheless, the good gourmand will be tempted to make cheese and will need some information. It is important to know that cheese is obtained through the...

  29. Fruits of the Harvest
    (pp. 134-135)

    When an apple is cut or peeled, its surface, which is initially white, turns brown within minutes. Apricots, pears, cherries, and peaches do not brown, but, even worse, they blacken! Bananas and potatoes turn pink before turning brown. Lemons and oranges, on the other hand, do not brown. Does their natural acidity protect them?

    Absolutely. If certain fruits brown when they are cut, it is because the knife damages some of their cells, releasing their contents and especially some enzymes that were enclosed in special compartments.

    More precisely, the enzymes, called polyphenolases, oxidize the colorless polyphenol molecules of the fruits...

  30. Ices and Sorbets
    (pp. 136-138)

    The scourge of ices and sorbets is the ice crystal. When it seems to be absent, the dessert is delicious, velvety smooth, and melting in the mouth. But when it is present, a horrible sensation of broken glass in the mouth ruins the pleasure that the dish’s thousand shimmering reflections had promised.

    Physicists and especially crystallographers are well acquainted with crystals. They know that in order to obtain large ones, the parent solution must not be moved and as slow a growth as possible must be encouraged.

    The cook, who desires the opposite effect, must thus agitate such solutions as...

    (pp. 139-144)

    To become a good cook, Escoffier said, you must first try your hand at pastries, because that is the best school for learning correct proportions. Let us add that pastries are also a wonderful domain for the physical chemist . . . and for the gourmand. Isn’t that where we find whipped cream, mousses, candied fruit, and a thousand other preparations that science can help us make successfully without mistakes?

    Many cakes begin with a solid base that supports the rest of the creation. How to obtain one that is airy and melting? Spongy or foamy textures are essential. The...

    (pp. 145-150)

    Everyone knows that pastry doughs are basically flour, water, and butter. Nevertheless, tart dough is nothing at all like puff pastry, which differs considerably from sweet shortbread dough. Why do the same ingredients produce such different results? Because the hand of the pastry cook comes into play. Let us examine how.

    The simplest dough is prepared with just flour and water, mixed in proportions that yield a substance with the consistency of thick putty that does not stick to the fingers. In the making of this dough, water is introduced between the countless starch granules in the flour, and it...

  33. Sugar
    (pp. 151-152)

    Louis XIII’s cook, Jean de la Varenne, said that “a man who attaches great importance to dessert after a good meal is a fool who spoils his spirit with his stomach.” Some gourmands will share his opinion, but many of us, even as adults, have not lost our immoderate taste for sugar and its various forms . . . like caramel.

    Why its golden color? Why its inimitable flavor? Table sugar is composed of a molecule called sucrose, a glucose ring with six carbon atoms, bound by an oxygen atom to a fructose ring.

    When this molecule is heated, it...

  34. Bread
    (pp. 153-164)

    Many city dwellers have forgotten the taste of their origins. Sometimes they have also forgotten what, after a millennium of civilization, has become second nature to humans: the preparation of bread. A few elevator stops separate them from the baker, who lets them benefit from his professional expertise, his specialized equipment . . . and his appetizing breads.

    Why should we go to the trouble of arduous kneading and baking, with sometimes mediocre results? Will we ever attain those golden baguettes, those crusty, sweet-smelling breads neatly lined up behind our pleasant baker? Where can we find the flour and yeast...

  35. Wine
    (pp. 165-175)

    Writing down “wine” is already to ask a question. Did I say a question? No, a thousand of them! Because of its complexity and diversity, wine escapes the closest analysis. We perceive the subtle odors, search for memories, often get lost there. Thus I will not proceed in my usual manner. With more modest goals than in other chapters, I will be content to try and describe this divine product, in order to appreciate it better. This is not just an intellectual exercise, because according to Grimod de la Reynière, “the mouthfuls most discussed taste best.”

    Because wine is a...

  36. The Alcohols
    (pp. 176-178)

    In the past, distillers set up shop on the outskirts of villages with their carts and their copper stills to distill cider, wine, and the fermented juice of various fruits: pears, apples, plums. The principle behind distillation is simple. Since ethylic alcohol boils at 78°C (172°F) and water boils at 100°C (212°F), alcohol is separated from water by heating a mixture of the two substances; the alcohol, which evaporates first, is condensed in a coil, while the water remains in the vat.

    In practice, the operation is a bit more complex, because the aim is to recuperate not pure alcohol...

  37. Jams
    (pp. 179-183)

    Jam? Preparing it is so simple that we could leave it to children if they did not run the risk of getting burned: heat a mixture of sugar, a trace of water, fruit, and seal it in a canning jar. And there you have it!

    You may encounter a few difficulties in the details, however, not from the point of view of conservation but regarding consistency. How to obtain jam that holds together? Why do some fruits make better jam than others?

    The key to jam is a long molecule called pectin, present in the walls of vegetable cells in...

  38. Tea
    (pp. 184-187)

    In Southeast Asia, tea leaves were chewed or infused in prehistoric times. Tea has been cultivated in China since the fourth century before our era, and its use was transported to Japan in about the sixth century. But if the practice of infusion is universal, all herbs and plants are not endowed with the same capacity for releasing scents and flavors.

    Orientalism and, it must be confessed, a certain perfectionism about tea and its preparation, established its use in our countries, where we have not entirely forgotten that country people have made infusions from plants since time immemorial: mint, linden...

  39. Cold and Cool
    (pp. 188-189)

    How to keep fruits and vegetables for a long time? By putting them in a cool place as quickly as possible, by isolating the ones that are already damaged, and by carefully cleaning the containers where they are kept. Of all the benefits of science and technology, one of the most misunderstood—because it is so familiar—is refrigeration.¹ Nevertheless, only the carefully considered use of refrigeration produces good results. Here is a way to use it that owes much to the findings of the team of agronomists at the INRA research center in Monfavet and to the work entitled...

  40. Vinegar
    (pp. 190-191)

    Since Louis Pasteur’s time, we have known that vinegar is formed through the fermentation of ethylic alcohol by a single-cell fungus related to yeast, Mycoderma aceti. In conditions of limited acidity, with certain concentrations of alcohol, and in the presence of nutritive compounds such as the proteins present in wine, these mycoderms develop and form a grayish veil, sometime as fine as silk, sometime more solid.

    The fungus absorbs oxygen from the air and fixes it on the alcohol, transforming the alcohol into acetic acid, which, as a solution in water, constitutes vinegar.

    Mycoderms like acid products and develop better...

  41. Kitchen Utensils
    (pp. 192-195)

    Silver place settings, the treasures of our grandmothers, ornaments to our tables, a pleasure to the eye, have a serious inconvenience. They tarnish. If they come in contact with egg? Their radiance seems irremediably lost. If they are washed in a sink that contains less noble metals? They darken as if they were too fine to endure contact with commoners.

    How to recover them? The solution is simple. Remedies abound, but some are not reliable. I offer you here my full assurance of the perfect effectiveness of the following two remedies.

    The first possibility involves the use of hydrogen peroxide....

  42. Mysteries of the Kitchen
    (pp. 196-198)

    In this exploration of the wonderful world of the gourmand, we have had the opportunity to discover some answers. Nevertheless, cooking is teeming with questions. It is my dream that science will help us to answer them.

    Here are just a few:

    Supposedly, a sabayon can boil without turning if a pinch of flour is added to the mixture of egg yolk beaten into a liquid (water, wine, juice . . . ). Experience shows that this precaution is effective. How does the flour act to protect the sauce?

    If egg yolk is added to coarse sugar without being worked...

  43. Glossary
    (pp. 199-210)
  44. Index
    (pp. 211-220)