Molecular Gastronomy: Exploring the Science of Flavor (5 page)

I may say?

friend: What could you possibly say about me? Don’t get the idea that you can scare

me off!

au thor: What I shan’t say is that our native land prides itself on having produced you;

that at twenty-four you had already published a textbook which has since become a clas-

sic; that your deserved reputation inspires great confidence in you; that your general

appearance reassures the sick; that your dexterity astounds them; that your sympathy

comforts them. All this is common knowledge. But I shall reveal to the whole of Paris

(
here I draw myself up
), to all of France (
I swell with oratorical rage
), to the Universe itself,

your only fault!

friend (
gravely
): And what is that, may I ask?

au thor: An habitual vice, which all my exhortations have not corrected.

friend (
horrified
): Tell me! Don’t torture me like this!

au thor: You eat too fast!

[here the friend picks up his hat, and exits smiling, fairly well

convinced that he had made a convert.]

Introduction
| 15

The latest studies of the present generation of physiologists of flavor are

reported in the second part of the book. These studies, which, unlike Brillat-

Savarin’s literary investigations, constitute the true physiology of flavor, have a

direct usefulness in the kitchen for those who are bold enough to apply them.

Yet a more complete science remains to be built on this base. Recall the defini-

tion I gave earlier of molecular gastronomy. Only the dictums, proverbs, and

rules that have been shown to be sound can be placed at the heart of the new

science that is needed. This means that culinary practice must henceforth be

based on a genuine physiology of flavor. In asking how are individual dishes

to be prepared, however, we are dealing with something rather different: the

modeling of culinary operations. And this modeling must be based on an

understanding of the physical transformations to which foods are subjected

in cooking.

This is the subject of the third part of the book. However, note that the

“intelligent knowledge” the reader will find there must be judged with refer-

ence to the peculiar situation in which cooks find themselves.
Sutor ne supra

crepidam iudicaret:
Let not the cobbler criticize [a work of art] above the shoe.

But cooks have no choice but to judge above and beyond the pan, for they know

that this work is not for the stomach but for the heart and the soul. And this

is why seemingly useless explorations find their place here—for love of the

beauty of pure knowledge.

Consider the egg yolk—the ordinary egg yolk, which generations of cooks

have used without looking at it any longer than was necessary to prevent it from

being broken or spilled. Yet it possesses a complex and unsuspected structure,

which science has disclosed to us. No longer can the sight of an egg yolk be

thought uninteresting. For boredom is born not of uniformity but of a certain

offhandedness, a lack of deference. Thanks to science, which teaches us that

even the yolk of an egg deserves to be the object of curiosity and admiration,

we have no reason to be bored in the kitchen again.

Obviously molecular gastronomy does not aim solely at attaining pure

knowledge of this sort, because it seeks also to give practical knowledge a sound

basis by explaining why successful recipes work and why mistakes occur. Thus,

for example, if you ask why lumps form when flour is placed in a hot liquid,

you will at once be led to useful conclusions that allow certain culinary tech-

niques to be rationalized and refined.

16 | introduc tion

I propose a new article of faith: Whoever understands the reasons for the

results he or she obtains in the kitchen can improve on them. This is why I

devote so much attention at the outset to criticizing traditional recipes. What if

one follows a recipe for making mayonnaise to the letter, but the sauce breaks?

As a hostage to the recipe one will have no alternative but to throw out the of-

fending egg, mustard, and oil. But the cook who understands that mayonnaise

is an emulsion—a dispersion of oil droplets in water (from the yolk and vin-

egar)—will be able to save the sauce, not by adding another egg (as the leading

authorities advise) but by decanting the oil and once again dispersing it in the

watery ingredients.

The whole third part of the book therefore is concerned with improv-

ing recipes and preparations. Reasoned analysis, allied with the ideal of

perfectibility, is what gives cooking its soul. The spirit of Brillat-Savarin

lives on.

In exploring physical and chemical mechanisms of cooking we will find

ample grounds for modifying classic recipes. Consider once again the soufflé.

First we test the maxim that the whipped egg whites must be firm; then we an-

alyze the way in which we perceive the light, airy texture of the dish. From this

we draw conclusions about what a soufflé ideally ought to be: Rational analysis

of the classic recipe shows that a soufflé should be heated from below. But now

we find ourselves confronted with an awkward situation. Recent studies—ex-

perimental and theoretical alike, because the two obviously go together—have

shown that the classic method of cooking soufflés in the oven is not indispens-

able. What are we to do? Do we abandon the oven, out of distrust of tradition,

in order to produce a better soufflé? Or do we go on following the teachings

of the old masters, forgetting that things such as mayonnaise and puff pastry,

centuries ago, were themselves innovations?

The fourth part of this book frankly rejects conservatism and resistance

to change in the name of another tradition: intelligent knowledge. It is in the

name of this tradition that we undertake to devise new chocolate mousses, that

we resolve to abandon the useless clarification of stocks, that we generalize

from the traditional aioli (a garlic emulsion) to produce a new class of flavored

mayonnaises, and that, despite opposition from defenders of tradition who

fear the temptations of novelty, we dare to conduct chemistry experiments in

our own kitchens.

Introduction
| 17

The fact of the matter is that we do both chemistry and physics whenever

we make an emulsified sauce or grill a piece of meat. Nonetheless, we are like

Molière’s Monsieur Jourdain, not realizing that we have been doing chemistry

and physics all along. What is more, satisfied with what we have achieved, we

do not look for ways to achieve something better. In the fourth part of the book

it is therefore the soul of cooking that I insist on. For in seeking to understand

the reasons for what we do in the kitchen we seek not to poison ourselves but

rather to enjoy flavors that until now we have only dreamed of. Let us go about

our cooking, then, with full knowledge of what it actually involves.

18 | introduc tion

Secrets of the Kitchen

Meat loses its juices no less readily when it is placed first in boiling water

than in cold water.

b e e f s t o c k ( a l s o c a l l e d b r o t h o r b o u i l l o n ), chef Jules Gouffé

wrote in
Le livre de cuisine
(1867), is “the soul of ordinary cooking.” Rather than

water, which has no taste, cooks have long used wine or the liquid obtained by

simmering meats and vegetables in water. This liquid traditionally is served as

a first course, but it is used also to moisten various dishes and as an element

in the preparation of sauces. How should it be made?

Cookbooks are filled with admonitions. “The gradual heating of the liquid,”

states
Le livre de cuisine de Mme. E. Saint-Ange
(1927), “is of the highest impor-

tance for the clarity as well as for the flavorfulness of the broth.” The idea that

meat ought to be cooked in water that is initially cold was advanced almost

a century earlier by Marie-Antoine Carême, perhaps the most famous of all

French cooks, also known as the “cook of emperors” for his service in Russia to

the Tsar and in England to the Prince of Wales. Carême proposed an explana-

tion in
L’Art de la cuisine française au XIXe siècle
(1833): “The broth must come

to a boil very slowly, otherwise the albumin coagulates, hardens; the water, not

having had the necessary time to penetrate the meat, prevents the gelatinous

part of the osmazome from detaching itself from it.”

Some ten years before Carême, Brillat-Savarin wrote that “to have a good

broth, it is necessary that the water heat slowly, in order that the albumin does

not coagulate inside [the meat] before being extracted; and it is necessary that

the boiling be scarcely perceptible, so that the various parts that are succes-

| 23

sively dissolved are able to blend intimately and readily.” The release of the

meat’s juices is related, then, to the clarity of the broth.

Are we justified in supposing that the meat yields different quantities of

juice depending on whether it is initially placed in hot water or cold water?

Plainly everything depends on the length of cooking. Gouffé argued that the

cooking must last several hours: “There comes a moment when the meat is

cooked and has nothing more to give you in the way of juice or aroma. To let it

remain in the pot after it has been completely exhausted by cooking, far from

improving the broth, risks spoiling it. I advise a limit of five hours for a large

pot-au-feu
.”

It is hard to understand why, after five hours of cooking, the smell and taste

should still depend on the temperature of the water at the outset. On the other

hand, it is easy to see that the mechanical agitation of the broth places in sus-

pension particles that have been separated from the meat, leading to a cloudy

broth that will then have to be clarified, at the risk of weakening its flavor.

Since 1995 my colleagues and I have been comparing various cooking

methods for broths. It soon became apparent that broths begun with boiling

water were cloudier. Nonetheless, the problem of the initial temperature of the

water persisted, despite the work of Justus von Liebig (1803–1873), universally

known for his pioneering studies in organic chemistry and for his broths and

meat extracts.

Liebig claimed that the essential nutrients of meat are found not in its

muscle fibers but in its fluids, which are lost during roasting and broth mak-

ing. When the meat is plunged into boiling water and the temperature then

reduced to a simmer, Liebig wrote in an article published in 1848, “the albu-

min immediately coagulates from the surface [of the meat] inwards, and in

this state forms a crust or shell, which no longer permits the external water

to penetrate into the interior of the mass of flesh. But the temperature is

gradually transmitted to the interior, and there effects the conversion of the

raw flesh into the state of boiled or roasted meat. The flesh retains its juici-

ness, and is quite as agreeable to the taste as it can be made by roasting; for

the chief part of the sapid constituents of the mass is retained, under these

circumstances, in the flesh.” Conversely, in order to produce a good broth,

he recommended against putting the meat in hot water because otherwise

the juices would be confined in the meat and one would end up with a taste-

less broth.

24 | secrets of the kitchen

These precepts formed the basis for a commercial enterprise. Using a vac-

uum to evaporate the broth produced by cooking minced meat in cold water,

Liebig obtained a “beef extract” that he sold throughout the world, simultane-

ously propagating the theory that broth is best made starting from cold water.

Liebig was a good chemist, but on this subject he did no more than copy the

writings of Brillat-Savarin, who was neither a scientist nor a cook, a half-centu-

ry earlier. There is no question that plunging meat into boiling water blanches