Whole Egg Egg White Egg White Egg Yolk Egg Yolk

Weight 55 g 55 g 38 g 38 g 17 g 17 g

Protein 6.6 g 6.6 g 3.9 g 3.9 g 2.7 g 2.7 g

Carbohydrate 0.6 g 0.6 g 0.3 g 0.3 g 0.3 g 0.3 g

Fat 6 g 6 g 0 0.

6 g 6 g

Monounsaturated 2.5 g 2.5 g 0 0.

2.5 g 2.5 g

Polyunsaturated 0.7 g 0.7 g 0 0.

0.7 g 0.7 g

Saturated 2 g 2 g 0 0.

2 g 2 g

Cholesterol 213 mg 213 mg 0 0.

213 mg 213 mg

Sodium 71 mg 71 mg 62 mg 62 mg 9 mg 9 mg

Calories 84 84.

20 20.

64 64.

Egg Allergies Eggs are one of the commonest foods to which people develop food allergies. Portions of the major egg-white protein ovalb.u.min appear to be the usual culprits. The immune system of sensitive people interprets these parts of ovalb.u.min to be a threat, and mounts a ma.s.sive and self-destructive defense that can take the form of fatal shock. Since a sensitivity to egg white often forms in early life, pediatricians commonly recommend that children not eat egg whites until after the age of one. Egg yolks are far less allergenic and can safely be eaten by nearly all infants. Eggs are one of the commonest foods to which people develop food allergies. Portions of the major egg-white protein ovalb.u.min appear to be the usual culprits. The immune system of sensitive people interprets these parts of ovalb.u.min to be a threat, and mounts a ma.s.sive and self-destructive defense that can take the form of fatal shock. Since a sensitivity to egg white often forms in early life, pediatricians commonly recommend that children not eat egg whites until after the age of one. Egg yolks are far less allergenic and can safely be eaten by nearly all infants.

Egg Quality, Handling, and Safety What is a good egg? An intact, uncontaminated egg with a strong sh.e.l.l; a firm yolk and yolk membrane, which prevents the yolk from breaking and mixing with the white; and a high proportion of cohesive, jellylike thick white compared to runny thin white.

And what makes a good egg? Above all, a good hen: a hen of a select laying breed that is healthy and not approaching the end of a laying year, when sh.e.l.ls and whites deteriorate (this stage is shortened by restricting the hen's food, which induces her to molt and reset her biological clock). A nutritious feed, free of contaminants, and without ingredients (fish meal, raw soy meal) that impart off-flavors. And careful evaluation and handling once the egg leaves the hen.

In order to determine egg quality without actually breaking them, producers candle candle their eggs, or place them in front of a light bright enough to pa.s.s through them and illuminate their contents. (Candle and eye were the original equipment; today electric lights and scanners do the work automatically.) Candling readily detects cracks in the sh.e.l.l, harmless but unappealing blood spots on the yolk (from burst capillaries in the hen's ovary or yolk sac), and "meat spots" in the whites (either brown blood spots or tiny bits of tissue sloughed off from the oviduct wall), and large air cells, all characteristics that relegate an egg to the lower grades. To determine the condition of the yolk and white, the egg is quickly twirled. The yolk's shadow will remain indistinct if its membrane is strong enough and the white thick enough to have kept it from getting close to the sh.e.l.l. If the yolk is easy to see, then it's too easily deformed or mobile, and the egg is of lower quality. their eggs, or place them in front of a light bright enough to pa.s.s through them and illuminate their contents. (Candle and eye were the original equipment; today electric lights and scanners do the work automatically.) Candling readily detects cracks in the sh.e.l.l, harmless but unappealing blood spots on the yolk (from burst capillaries in the hen's ovary or yolk sac), and "meat spots" in the whites (either brown blood spots or tiny bits of tissue sloughed off from the oviduct wall), and large air cells, all characteristics that relegate an egg to the lower grades. To determine the condition of the yolk and white, the egg is quickly twirled. The yolk's shadow will remain indistinct if its membrane is strong enough and the white thick enough to have kept it from getting close to the sh.e.l.l. If the yolk is easy to see, then it's too easily deformed or mobile, and the egg is of lower quality.

Egg Grades Eggs sold in stores are usually (but not mandatorily) cla.s.sified by United States Department of Agriculture (USDA) grades. Egg grade has nothing to do with either freshness or size, and is not a guarantee of egg quality in your kitchen. It's an approximate indication of the quality of the egg back at the ranch, at the time it was collected. Because candling isn't foolproof, USDA definitions allow several eggs per carton to be below grade at the time of packing. Once the eggs have arrived in stores, the below-grade allowance doubles, because egg quality naturally declines with time, and jostling and vibration during transport can cause the white to thin out.

Generally, only the two top grades, AA and A, are seen in stores. If you're going to use eggs fairly soon and will be scrambling them or making a custard or pancakes, then the higher grade isn't worth the higher price. But if you go through eggs slowly, or like your hard-boiled yolks well centered and your poached and fried eggs neat and compact, or are planning to make a meringue, souffle, or egg-leavened cake, then you may be better off with the premium grade, with its thicker white and a yolk membrane less likely to leak foam-lowering yolk into the white.

In any case, the quality of a carton of eggs depends mainly on how old they are. Even Grade AA eggs eventually develop flat yolks and thin whites. So be sure to check the sell-by date stamped on the carton (usually four weeks from the packing date; sometimes the pack date itself is indicated by a single number from 1 to 365), and choose the carton with the latest date. Fresh grade A eggs can be a better buy than old grade AA.

Deterioration in Egg Quality Designed as it was to protect itself for the duration of the chick's development, the egg is unique among our raw animal foods in its ability to remain edible for weeks, as long as it's kept intact and cool. Even so, the moment the egg leaves the hen, it begins to deteriorate in important ways. There is a fundamental chemical change: both the yolk and the white get more alkaline (less acidic) with time. This is because the egg contains carbon dioxide, which takes the form of carbonic acid when it's dissolved in the white and yolk, but is slowly lost in its gaseous form through the pores in the sh.e.l.l. The pH scale provides a measure of acidity and alkalinity (p. 795). On the pH scale, the yolk rises from a slightly acidic pH of 6.0 to a nearly neutral 6.6, while the alb.u.men goes from a somewhat alkaline 7.7 to a very alkaline 9.2 and sometimes higher.

This alkalinization of the white has highly visible consequences. Because alb.u.men proteins at the pH of a fresh egg tend to cl.u.s.ter in ma.s.ses large enough to deflect light rays, the white of a fresh egg is indeed cloudily white. In more alkaline conditions these proteins repel each other rather than cl.u.s.ter, so the white of an older egg tends to be clear, not cloudy. And the white gets progressively more runny with time: the proportion of thick alb.u.men to thin, initially about 60% to 40%, falls below 5050.

The relatively minor change in yolk acidity is less important than a simple physical change. The yolk starts out with more dissolved molecules than the white, and this osmotic imbalance creates a natural pressure for water in the white to migrate across the yolk membrane. At refrigerator temperatures, about 5 milligrams of water cross into the yolk each day. This influx causes the yolk to swell, which stretches and weakens the yolk membrane. And the added water thins the yolk dramatically.

A Home Test Finally, the egg as a whole also loses moisture through its porous sh.e.l.l, so the contents of the egg shrink, and the air cell at the wide end expands. Even an oil-coated egg in a humid refrigerator loses 4 milligrams of water to evaporation each day. The cook can use this moisture loss to estimate the freshness of an egg. A new egg with an air s.p.a.ce less than Finally, the egg as a whole also loses moisture through its porous sh.e.l.l, so the contents of the egg shrink, and the air cell at the wide end expands. Even an oil-coated egg in a humid refrigerator loses 4 milligrams of water to evaporation each day. The cook can use this moisture loss to estimate the freshness of an egg. A new egg with an air s.p.a.ce less than 1 1/8 inch/3 mm deep is denser than water and will sink to the bottom of a bowl of water. As an egg ages and its air cell expands, it gets progressively less dense, and the wide end of the egg rises higher and higher in the water. An egg that actually floats is very old and should be discarded. Around 1750, the English cookbook author Hannah Gla.s.se gave two ways of determining the freshness of an egg, an important talent at a time when it might have been sitting for some time in an odd corner of the yard. One is to feel how warm it is - probably less than reliable - but the second indirectly a.s.says the air cell: "[Another way] to know a good egg, is to put the egg into a pan of cold water; the fresher the egg the sooner it will fall to the bottom; if rotten, it will swim at the top." inch/3 mm deep is denser than water and will sink to the bottom of a bowl of water. As an egg ages and its air cell expands, it gets progressively less dense, and the wide end of the egg rises higher and higher in the water. An egg that actually floats is very old and should be discarded. Around 1750, the English cookbook author Hannah Gla.s.se gave two ways of determining the freshness of an egg, an important talent at a time when it might have been sitting for some time in an odd corner of the yard. One is to feel how warm it is - probably less than reliable - but the second indirectly a.s.says the air cell: "[Another way] to know a good egg, is to put the egg into a pan of cold water; the fresher the egg the sooner it will fall to the bottom; if rotten, it will swim at the top."

Three different grades of eggs. The AA egg has a high proportion of thick white and a firm, rounded yolk. The A egg has a less thick alb.u.men and a weaker yolk membrane, so it spreads more when cracked into a pan. The B egg spreads even further, and its yolk membrane is easily broken.

All of these trends are probably part of the normal development of the egg. The increase in alkalinity makes the alb.u.men even less hospitable to invading bacteria and molds. The thinning of the alb.u.men allows the yolk to rise and the embryo to approach the sh.e.l.l, its early source of oxygen, and may make it easier for the embryo to tap the sh.e.l.l's calcium stores. A weaker yolk membrane could mean an easier attachment to the sh.e.l.l membranes. And the larger air cell gives the chick more oxygen for its first few breaths.

These changes may be good for the chick, but they're mostly bad for the cook. A thinner white is runnier in the pan; a flabby yolk membrane is more likely to break when the egg is cracked open; and a large air cell means an irregular shape for a whole hard-cooked egg. The only culinary benefit to an older egg is that it's easier to peel.

Handling and Storing Eggs Producers handle eggs in ways that are meant to slow down the inevitable deterioration in quality. Eggs are gathered as shortly after laying as possible and immediately cooled. In the United States, they are then washed in warm water and detergent to remove the thousands of bacteria deposited on the sh.e.l.l during its pa.s.sage through the hen's cloacal opening. In the past, the washed eggs were given a fresh coat of mineral oil to r.e.t.a.r.d the loss of both CO2 and moisture; today, with most eggs getting to market just two days after laying and refrigerated during shipping as well as storage, oiling is limited to long haul delivery routes. and moisture; today, with most eggs getting to market just two days after laying and refrigerated during shipping as well as storage, oiling is limited to long haul delivery routes.

Egg Storage at Home: Cold, Still, Sealed Egg quality deteriorates as much in a day at room temperature as in four days under refrigeration, and salmonella bacteria (p. 83) multiply much faster at room temperature. So it's best to buy your eggs cold - out of the cooler, not off an open shelf - and keep them cold. Agitation thins the white, so an inner refrigerator shelf is preferable to the door. An airtight container is better than the standard loose carton at slowing moisture loss and the absorption of odors from other foods, although it accentuates the stale flavor that gradually develops in the eggs themselves. Bought fresh and treated with care, eggs should keep for several weeks in the sh.e.l.l. Once broken open, they're far more susceptible to spoilage and should be used promptly or frozen. Egg quality deteriorates as much in a day at room temperature as in four days under refrigeration, and salmonella bacteria (p. 83) multiply much faster at room temperature. So it's best to buy your eggs cold - out of the cooler, not off an open shelf - and keep them cold. Agitation thins the white, so an inner refrigerator shelf is preferable to the door. An airtight container is better than the standard loose carton at slowing moisture loss and the absorption of odors from other foods, although it accentuates the stale flavor that gradually develops in the eggs themselves. Bought fresh and treated with care, eggs should keep for several weeks in the sh.e.l.l. Once broken open, they're far more susceptible to spoilage and should be used promptly or frozen.

Storage PositionDoes it make a difference what posture we store our eggs in? Studies in the 1950s found alb.u.men quality to decline more slowly in eggs stored blunt end up, and many states adopted this as the official position for packing egg cartons. Studies in the 1960s and '70s, when retailers began to stack the cartons on their side to display the top label, found that posture doesn't affect alb.u.men quality. Eggs that are stored on their sides give somewhat better-centered yolks when hard-cooked, perhaps because both yolk cords fight equally against gravity.

Freezing Eggs Eggs can be stored frozen for several months in airtight containers. Remove them from the sh.e.l.l, which would shatter, as its contents expand during freezing. Allow some room for expansion in the containers, and press plastic wrap onto the surface to prevent freezer burn (see p. 146) before covering with a lid. Whites freeze fairly well; they lose only a modest amount of their foaming power. Yolks and blended whole eggs, however, require special treatment. Frozen as is, they thaw to a pasty consistency and can no longer be readily combined with other ingredients. Thoroughly mixing the yolks with either salt, sugar, or acid will prevent the yolk proteins from aggregating, and leaves the thawed mixture fluid enough to mix. Yolks require 1 teaspoon salt, 1 tablespoon sugar, or 4 tablespoons lemon juice per pint (respectively 5 gm, 15 gm, or 60 ml per half liter), and whole eggs half these amounts. The equivalent of a U.S. Large egg is 3 tablespoons whole egg, or 2 tablespoons white and 1 tablespoon yolk. Eggs can be stored frozen for several months in airtight containers. Remove them from the sh.e.l.l, which would shatter, as its contents expand during freezing. Allow some room for expansion in the containers, and press plastic wrap onto the surface to prevent freezer burn (see p. 146) before covering with a lid. Whites freeze fairly well; they lose only a modest amount of their foaming power. Yolks and blended whole eggs, however, require special treatment. Frozen as is, they thaw to a pasty consistency and can no longer be readily combined with other ingredients. Thoroughly mixing the yolks with either salt, sugar, or acid will prevent the yolk proteins from aggregating, and leaves the thawed mixture fluid enough to mix. Yolks require 1 teaspoon salt, 1 tablespoon sugar, or 4 tablespoons lemon juice per pint (respectively 5 gm, 15 gm, or 60 ml per half liter), and whole eggs half these amounts. The equivalent of a U.S. Large egg is 3 tablespoons whole egg, or 2 tablespoons white and 1 tablespoon yolk.

Egg Safety: The Salmonella Problem Beginning around 1985, a hitherto minor bacterium called Salmonella enteritidis Salmonella enteritidis was identified as the culprit in growing numbers of food poisonings in continental Europe, Scandinavia, Great Britain, and North America. Salmonella can cause diarrhea or more serious chronic infection of other body organs. Most of these outbreaks were a.s.sociated with the consumption of raw or lightly cooked eggs. Further investigation demonstrated that even intact, clean, Grade A eggs can harbor large numbers of salmonella. In the early 1990s, U.S. health authorities estimated that perhaps one egg in 10,000 carried this particularly virulent form of salmonella. Thanks to a variety of preventive measures, the prevalence of contaminated eggs is now much lower - but it's not zero. was identified as the culprit in growing numbers of food poisonings in continental Europe, Scandinavia, Great Britain, and North America. Salmonella can cause diarrhea or more serious chronic infection of other body organs. Most of these outbreaks were a.s.sociated with the consumption of raw or lightly cooked eggs. Further investigation demonstrated that even intact, clean, Grade A eggs can harbor large numbers of salmonella. In the early 1990s, U.S. health authorities estimated that perhaps one egg in 10,000 carried this particularly virulent form of salmonella. Thanks to a variety of preventive measures, the prevalence of contaminated eggs is now much lower - but it's not zero.

Precautions Until the day of the certified salmonella-free egg, all cooks should know how to minimize the risk to themselves and to others, particularly the very young and very old and people with weakened immune systems. The best way to reduce the already small chance of using a badly contaminated egg is to buy only refrigerated eggs and to speed them into your own refrigerator. Cook all egg dishes sufficiently to kill any bacteria that might be present. This generally means holding a temperature of at least 140F/60C for 5 minutes, or 160F/70C for 1 minute. Egg yolks will remain runny at the first temperature, but will harden at the second. For many lightly cooked egg dishes - soft-boiled and poached eggs, for example, and the yolk-based sauces - it's possible to modify traditional recipes so as to eliminate any salmonella that might be present (see box, p. 91). Until the day of the certified salmonella-free egg, all cooks should know how to minimize the risk to themselves and to others, particularly the very young and very old and people with weakened immune systems. The best way to reduce the already small chance of using a badly contaminated egg is to buy only refrigerated eggs and to speed them into your own refrigerator. Cook all egg dishes sufficiently to kill any bacteria that might be present. This generally means holding a temperature of at least 140F/60C for 5 minutes, or 160F/70C for 1 minute. Egg yolks will remain runny at the first temperature, but will harden at the second. For many lightly cooked egg dishes - soft-boiled and poached eggs, for example, and the yolk-based sauces - it's possible to modify traditional recipes so as to eliminate any salmonella that might be present (see box, p. 91).

Pasteurized Eggs Three safer alternatives to fresh eggs are eggs pasteurized in the sh.e.l.l, liquid eggs, and dried egg whites, all of which are available in supermarkets. Intact eggs, blended whole eggs, or separated yolks and whites can all be pasteurized by careful heating to temperatures between 130 and 140F/5560C, just below the range in which the egg proteins begin to coagulate. Dried egg whites, which are reconst.i.tuted in water to make lightly cooked meringues, can be pasteurized either before or after the drying. For most uses, these products do an adequate job of replacing fresh eggs, though there is usually some loss in foaming or emulsifying power and in stability to further heating; and heating and drying do alter the mild egg flavor. Three safer alternatives to fresh eggs are eggs pasteurized in the sh.e.l.l, liquid eggs, and dried egg whites, all of which are available in supermarkets. Intact eggs, blended whole eggs, or separated yolks and whites can all be pasteurized by careful heating to temperatures between 130 and 140F/5560C, just below the range in which the egg proteins begin to coagulate. Dried egg whites, which are reconst.i.tuted in water to make lightly cooked meringues, can be pasteurized either before or after the drying. For most uses, these products do an adequate job of replacing fresh eggs, though there is usually some loss in foaming or emulsifying power and in stability to further heating; and heating and drying do alter the mild egg flavor.

The Chemistry of Egg Cooking: How Eggs Get Hard and Custards Thicken The most commonplace procedures involving eggs are also some of the most astonishing kitchen magic. You begin with a slippery, runny liquid, do nothing more than add heat, and presto: the liquid rapidly stiffens into a solid that you can cut with a knife. No other ingredient is as readily and drastically transformed as is the egg. This is the key to its great versatility, both on its own and as a structure builder in complex mixtures.

To what does the egg owe its constructive powers? The answer is simple: to its proteins and their innate capacity to bond to each other.

Protein Coagulation Pulling Proteins Together... The raw egg begins as a liquid because both yolk and white are essentially bags of water containing dispersed protein molecules, with water molecules outnumbering proteins 1,000 to 1. As molecules go, a single protein is huge. It consists of thousands of atoms bonded together into a long chain. The chain is folded up into a compact wad whose shape is maintained by bonds between neighboring folds of the chain. In the chemical environment of the egg white, most of the protein molecules acc.u.mulate a negative electrical charge and repel each other, while in the yolk, some proteins repel each other and some are bound up in fat-protein packages. So the proteins in a raw egg mostly remain compact and separate from one another as they float in the water. The raw egg begins as a liquid because both yolk and white are essentially bags of water containing dispersed protein molecules, with water molecules outnumbering proteins 1,000 to 1. As molecules go, a single protein is huge. It consists of thousands of atoms bonded together into a long chain. The chain is folded up into a compact wad whose shape is maintained by bonds between neighboring folds of the chain. In the chemical environment of the egg white, most of the protein molecules acc.u.mulate a negative electrical charge and repel each other, while in the yolk, some proteins repel each other and some are bound up in fat-protein packages. So the proteins in a raw egg mostly remain compact and separate from one another as they float in the water.

When we heat the egg, all its molecules move faster and faster, collide with each other harder and harder, and eventually begin to break the bonds that hold the long protein chains in their compact, folded shape. The proteins unfold, tangle with each other, and bond to each other into a kind of three-dimensional network. There's still much more water than protein, but the water is now divided up among countless little pockets in the continuous protein network, so it can't flow together any more. The liquid egg thus becomes a moist solid. And because the large protein molecules have cl.u.s.tered together densely enough to deflect light rays, the initially transparent egg alb.u.men becomes opaque.

How heat solidifies a liquid egg. Egg proteins begin as folded chains of amino acids (left) (left) . As they're heated, their increased motion breaks some bonds, and the chains unfold . As they're heated, their increased motion breaks some bonds, and the chains unfold (center). (center). The unfolded proteins then begin to bond to each other. This results in a continuous meshwork of long molecules The unfolded proteins then begin to bond to each other. This results in a continuous meshwork of long molecules (right) (right) , and a moist but solid egg. , and a moist but solid egg.

The other treatments that cause egg to firm up - pickling them in acid or salt, beating them into a foam - work in the same basic way, by overcoming the proteins' aloofness and encouraging them to bond to each other. When you combine treatments - adding both acid and heat, for example - you can achieve a whole range of consistencies and appearances, depending on the degree of protein unfolding and bonding: from tough to delicate, dry to moist, lumpy to jellylike, opaque to clear.

...But Not Too Too Close Close In nearly every egg dish we make, we want to bond a liquid - the egg alone or a mixture of eggs and other liquids - into a moist, delicate solid. Overcooking either gives the dish a rubbery texture or else curdles it into a mixture of hard lumps and watery liquid. Why? Because it bonds the proteins too exclusively to each other and squeezes out the water from the protein network. This is why it is that boiled or fried eggs lose water in the form of steam and get rubbery, while mixtures of eggs and other liquids separate into two phases, the added water and the solid lumps of protein. In nearly every egg dish we make, we want to bond a liquid - the egg alone or a mixture of eggs and other liquids - into a moist, delicate solid. Overcooking either gives the dish a rubbery texture or else curdles it into a mixture of hard lumps and watery liquid. Why? Because it bonds the proteins too exclusively to each other and squeezes out the water from the protein network. This is why it is that boiled or fried eggs lose water in the form of steam and get rubbery, while mixtures of eggs and other liquids separate into two phases, the added water and the solid lumps of protein.

The key to cooking egg dishes, then, is to avoid overcooking them and carrying coagulation too far. Above all, this means temperature control. For tender, succulent results, egg dishes should be cooked only just to the temperature at which their proteins coagulate, which is always well below the boiling point, 212F/100C. The exact temperature depends on the mixture of ingredients, but is usually higher than the temperature needed to kill bacteria and make the dish safe. (Warm but still liquid yolk is another story; see p. 91). Generally, plain undiluted eggs coagulate at the lowest temperatures. Egg white begins to thicken at 145F/63C and becomes a tender solid when it reaches 150F/65C. This solidification is due mainly to the most heat-sensitive protein, ovotransferrin, even though it's only 12% of the total protein. The major alb.u.men protein, ovalb.u.min, doesn't coagulate until about 180F/80C, at which temperature the tender white gets much firmer. (The last alb.u.men protein to coagulate is heat-resistant ovomucin, which is why the ovomucin-rich yolk cords remain liquid in scrambled eggs long after the rest has set.) The yolk proteins begin to thicken at 150F and set at 158F/70C, and whole egg - the yolk and white mixed together - sets around 165F/73C.

The Effects of Added Ingredients Eggs are often combined with other ingredients, from a sprinkling of salt or lemon juice, to spoonsful of sugar or cream, to cups of milk or brandy. Each of these additions affects egg-protein coagulation and the dish's consistency. Eggs are often combined with other ingredients, from a sprinkling of salt or lemon juice, to spoonsful of sugar or cream, to cups of milk or brandy. Each of these additions affects egg-protein coagulation and the dish's consistency.

The dilution of egg proteins in a custard. Left: Left: An egg is rich in proteins; when unfolded by cooking, they are numerous enough to form a firm solid network. An egg is rich in proteins; when unfolded by cooking, they are numerous enough to form a firm solid network. Center: Center: When mixed with milk or cream, whose proteins don't coagulate with heat, the egg proteins are greatly diluted. When mixed with milk or cream, whose proteins don't coagulate with heat, the egg proteins are greatly diluted. Right: Right: When a custard mix is cooked, the egg proteins unfold and form a solid meshwork, but that meshwork is open and fragile, and the custard's consistency is delicate. When a custard mix is cooked, the egg proteins unfold and form a solid meshwork, but that meshwork is open and fragile, and the custard's consistency is delicate.

Milk, Cream, and Sugar Dilute, Delay, and Tenderize When we dilute eggs with other liquids, we raise the temperature at which thickening begins. Dilution surrounds the protein molecules with many more water molecules, and the proteins must be hotter and moving around more rapidly in order to find and bond to each other at a noticeable rate. Sugar also raises the thickening temperature, and for the same reason: its molecules dilute the proteins. A tablespoon of sugar surrounds each protein molecule in a one-egg dish with a screen of several thousand sucrose molecules. Combine the diluting effects of water, sugar, and milk fat, and a custard mix containing a cup of milk, a tablespoon of sugar, and an egg begins to thicken not at 160F/70C, but at 175 or 180F/7880C. And because the protein network is stretched out into such a large volume - in a custard, the proteins from a single egg have to embrace not three tablespoons of liquid but 18 or 20! - the coagulum is far more delicate, and easily disrupted by overheating. At the extreme, in a concoction like eggnog or the Dutch brandy drink advocaat, the egg proteins are so diluted that they can't possibly accommodate all the liquid, and instead merely give it some body. When we dilute eggs with other liquids, we raise the temperature at which thickening begins. Dilution surrounds the protein molecules with many more water molecules, and the proteins must be hotter and moving around more rapidly in order to find and bond to each other at a noticeable rate. Sugar also raises the thickening temperature, and for the same reason: its molecules dilute the proteins. A tablespoon of sugar surrounds each protein molecule in a one-egg dish with a screen of several thousand sucrose molecules. Combine the diluting effects of water, sugar, and milk fat, and a custard mix containing a cup of milk, a tablespoon of sugar, and an egg begins to thicken not at 160F/70C, but at 175 or 180F/7880C. And because the protein network is stretched out into such a large volume - in a custard, the proteins from a single egg have to embrace not three tablespoons of liquid but 18 or 20! - the coagulum is far more delicate, and easily disrupted by overheating. At the extreme, in a concoction like eggnog or the Dutch brandy drink advocaat, the egg proteins are so diluted that they can't possibly accommodate all the liquid, and instead merely give it some body.

Acids and Salt Tenderize There's no truth to the common saying that acidity and salt "toughen" egg proteins. Acids and salt do pretty much the same thing to egg proteins. They get the proteins together sooner, but they don't let them get as There's no truth to the common saying that acidity and salt "toughen" egg proteins. Acids and salt do pretty much the same thing to egg proteins. They get the proteins together sooner, but they don't let them get as close close together. That is, acids and salt make eggs thicken and coagulate at a lower cooking temperature, but actually produce a more tender texture. together. That is, acids and salt make eggs thicken and coagulate at a lower cooking temperature, but actually produce a more tender texture.

The key to this seeming paradox is the negative electrical charge that most of the egg proteins carry, and that tends to keep them at a distance from each other. Acids - cream of tartar, lemon juice, or the juice of any fruit or vegetable - lower the pH of the egg, and thus diminish the proteins' mutually repelling negative charge. Similarly, salt dissolves into positively and negatively charged ions that cl.u.s.ter around the charged portions of the proteins and effectively neutralize them. In both cases, the proteins no longer repel each other as strongly, and therefore approach each other and bond together earlier in the cooking and unfolding process, when they're still mostly balled up and can't intertwine and bond with each other as tightly. In addition, coagulation of the yolk proteins and of some alb.u.men proteins depends on sulfur chemistry that is suppressed in acidic conditions (see the discussion of egg foams, p. 103). So eggs end up more tender when salted, and especially when acidified.

Cooks have known this for a long time. In Morocco, Paula Wolfert found that eggs are often beaten with lemon juice before long cooking to prevent them from becoming leathery; and Claudia Roden gives an Arab recipe for scrambled eggs made unusually creamy with vinegar (the eggs' alkalinity reduces the amount of free, odorous acetic acid, so the flavor is surprisingly subtle). Eggs scrambled with tart fruit juices were popular in 17th century France, and may have been the ancestors of lemon curd.

Early Acid-Tenderized EggsMarmelades or Scrambled Eggs and Verjus, Without b.u.t.ter or Scrambled Eggs and Verjus, Without b.u.t.terBreak four eggs, beat them, adjust with salt and four spoonsful of verjus [sour grape juice], put the mix on the fire, and stir gently with a silver spoon just until the eggs thicken enough, and then take them off the fire and stir them a bit more as they thicken. One can make scrambled eggs in the same way with lemon or orange juice...- Le Patissier francois, Le Patissier francois, ca. 1690 ca. 1690 The Chemistry of Egg Flavor Fresh eggs have a mild flavor that has proven difficult to a.n.a.lyze. The white contributes the main sulfury note, the yolk a sweet, b.u.t.tery quality. The aroma produced by a given egg is slightest immediately after laying, and gets stronger the longer it's stored before cooking. In general, egg age and storage conditions have a greater influence on flavor than the hen's diet and freedom to range. However, both diet and pedigree can have noticeable effects. Brown-egg breeds are unable to metabolize an odorless component of rapeseed and soy meals (choline), and their intestinal microbes then transform it into a fishy-tasting molecule (triethylamine) that ends up in the eggs. Fish-meal feeds and certain feed pesticides cause off-flavors. The unpredictable diet of truly free-range hens will produce unpredictable eggs.

Something between 100 and 200 compounds have been identified in the aroma of cooked eggs. The most characteristic is hydrogen sulfide, H2S. In large doses - in a spoiled egg or industrial pollution - H2S is very unpleasant. In a cooked egg it contributes the distinctively eggy note. It's formed predominantly in the white, when the alb.u.men proteins begin to unfold and free their sulfur atoms for reaction with other molecules, at temperatures above 140F/60C. The longer the alb.u.men spends at these temperatures, the stronger the sulfury aroma. Greater quant.i.ties of H2S are produced when the egg is older and the pH higher (the highly alkaline conditions in Chinese preserving methods, p. 116, also liberate copious amounts of H2S). Added lemon juice or vinegar reduces H2S production and its aroma. Because hydrogen sulfide is volatile, it escapes from cooked eggs during storage, so they get milder with time. Small quant.i.ties of ammonia are also created during cooking and make a subliminal contribution to egg flavor (but an overpowering one in Chinese preserved eggs).

Basic Egg Dishes Eggs Cooked in the Sh.e.l.l "Boiling an egg" is often taken as a measure of minimal competence in cooking, since you leave the egg safe in its sh.e.l.l and have only to keep track of the water temperature and the time. Though we commonly speak of hard- and soft-boiled eggs, boiling is not a good way to cook eggs. Turbulent water knocks the eggs around and cracks sh.e.l.ls, which allows alb.u.men to leak out and overcook; and for hard-cooked eggs, a water temperature way above the protein coagulation temperature means that the outer layers of the white get rubbery while the yolk cooks through. Soft-cooked eggs aren't cooked long enough to suffer in the same way, and should be cooked in barely bubbling water, just short of the boil. Hard-cooked eggs should be cooked at a bubble-less simmer, between 180 and 190F/8085C. Eggs in the sh.e.l.l can also be steamed, a technique that requires the least water and the least energy and time to heat the water. Leaving the lid slightly ajar on a gently bubbling steamer will reduce the effective cooking temperature to something below the boil and produce a tenderer white.

Telling Cooked Eggs from RawIt's easy to tell whether an intact egg is raw or already cooked. Give it a spin on its side. If it spins fast and smoothly, it's cooked. If it seems balky and wobbly, it's raw - the liquid insides slip and slosh and resist the movement of the solid sh.e.l.l.

Times and Textures Cooking times for in-sh.e.l.l eggs are determined by the desired texture (they also depend on egg size, starting temperature, and cooking temperature; the times here are rough averages). There's a continuum of eggs cooked in the sh.e.l.l for different periods of time. The French Cooking times for in-sh.e.l.l eggs are determined by the desired texture (they also depend on egg size, starting temperature, and cooking temperature; the times here are rough averages). There's a continuum of eggs cooked in the sh.e.l.l for different periods of time. The French oeuf a la coque oeuf a la coque ("from the sh.e.l.l") is cooked for only two or three minutes and remains semi-liquid throughout. Coddled or "soft-boiled" eggs, cooked 3 to 5 minutes, have a barely solid outer white, a milky inner white, and a warm yolk, and are spooned from the sh.e.l.l. The less familiar mollet eggs (from the French ("from the sh.e.l.l") is cooked for only two or three minutes and remains semi-liquid throughout. Coddled or "soft-boiled" eggs, cooked 3 to 5 minutes, have a barely solid outer white, a milky inner white, and a warm yolk, and are spooned from the sh.e.l.l. The less familiar mollet eggs (from the French molle, molle, "soft"), cooked for 5 or 6 minutes, have a semi-liquid yolk but a sufficiently firm outer white that they can be peeled and served whole. "soft"), cooked for 5 or 6 minutes, have a semi-liquid yolk but a sufficiently firm outer white that they can be peeled and served whole.

Hard-cooked eggs are firm throughout after cooking for 10 to 15 minutes. At 10 minutes the yolk is still dark yellow, moist, and somewhat pasty; at 15, it's light yellow, dry, and granular. Hard-cooking is sometimes prolonged for hours to heighten color and flavor (p. 89). Chinese tea eggs, for example, are simmered until set, then gently cracked, and simmered for another hour or two in a mixture of tea, salt, sugar, and flavorings to produce a marbled, aromatic, very firm white.

Hard-Cooked Eggs A properly prepared hard-cooked egg is solid but tender, not rubbery; its sh.e.l.l intact and easy to peel; its yolk well centered and not discolored; its flavor delicate, not sulfurous. Good texture and flavor are obtained by taking care not to overcook the eggs, which overcoagulates their proteins and generates too much hydrogen sulfide. Any method that keeps the cooking temperature well below the boil will help avoid overcooking, as will plunging the cooked eggs into ice water. Gentle cooking also takes care of most sh.e.l.l and yolk problems - but not all. A properly prepared hard-cooked egg is solid but tender, not rubbery; its sh.e.l.l intact and easy to peel; its yolk well centered and not discolored; its flavor delicate, not sulfurous. Good texture and flavor are obtained by taking care not to overcook the eggs, which overcoagulates their proteins and generates too much hydrogen sulfide. Any method that keeps the cooking temperature well below the boil will help avoid overcooking, as will plunging the cooked eggs into ice water. Gentle cooking also takes care of most sh.e.l.l and yolk problems - but not all.

Easily Cracked and Not So Easily Peeled Sh.e.l.ls A sh.e.l.l that cracks during hard cooking makes a mess and a sulfurous stink, while a sh.e.l.l that doesn't peel away cleanly makes an ugly, pockmarked egg. A traditional preventative measure for both problems is to poke a pinhole in the wide end of the sh.e.l.l, but studies have found that this doesn't make much difference. The best way to avoid cracking is to heat fresh eggs gently, without the turbulence of boiling water. On the other hand, the best guarantee of easy peeling is to use old eggs! Difficult peeling is characteristic of fresh eggs with a relatively low alb.u.men pH, which somehow causes the alb.u.men to adhere to the inner sh.e.l.l membrane more strongly than it coheres to itself. At the pH typical after several days of refrigeration, around 9.2, the sh.e.l.l peels easily. If you end up with a carton of very fresh eggs and need to cook them right away, you can add a half teaspoon of baking soda to a quart of water to make the cooking water alkaline (though this intensifies the sulfury flavor). It also helps to cook fresh eggs somewhat longer to make the white more cohesive, and to allow the white to firm up in the refrigerator before peeling. A sh.e.l.l that cracks during hard cooking makes a mess and a sulfurous stink, while a sh.e.l.l that doesn't peel away cleanly makes an ugly, pockmarked egg. A traditional preventative measure for both problems is to poke a pinhole in the wide end of the sh.e.l.l, but studies have found that this doesn't make much difference. The best way to avoid cracking is to heat fresh eggs gently, without the turbulence of boiling water. On the other hand, the best guarantee of easy peeling is to use old eggs! Difficult peeling is characteristic of fresh eggs with a relatively low alb.u.men pH, which somehow causes the alb.u.men to adhere to the inner sh.e.l.l membrane more strongly than it coheres to itself. At the pH typical after several days of refrigeration, around 9.2, the sh.e.l.l peels easily. If you end up with a carton of very fresh eggs and need to cook them right away, you can add a half teaspoon of baking soda to a quart of water to make the cooking water alkaline (though this intensifies the sulfury flavor). It also helps to cook fresh eggs somewhat longer to make the white more cohesive, and to allow the white to firm up in the refrigerator before peeling.

Off-Center Yolks and Flat-Bottomed Whites Well-centered yolks for attractive slices or stuffed halves are easiest to obtain from fresh, high-grade eggs with small air cells and plenty of thick alb.u.men. As eggs age, the alb.u.men loses water and becomes more dense, which makes the yolk rise. Industry studies have found that you can increase the proportion of centered yolks somewhat by storing eggs on their sides instead of their ends. Various cooking strategies have also been suggested, including rotating the eggs around their long axis during the first several minutes in the pot, and standing them on end. None of these is completely reliable. Well-centered yolks for attractive slices or stuffed halves are easiest to obtain from fresh, high-grade eggs with small air cells and plenty of thick alb.u.men. As eggs age, the alb.u.men loses water and becomes more dense, which makes the yolk rise. Industry studies have found that you can increase the proportion of centered yolks somewhat by storing eggs on their sides instead of their ends. Various cooking strategies have also been suggested, including rotating the eggs around their long axis during the first several minutes in the pot, and standing them on end. None of these is completely reliable.

Green Yolks The occasional green-gray discoloration on the surface of hard-cooked yolks is a harmless compound of iron and sulfur, ferrous sulfide. It forms at the interface of white and yolk because that's where reactive sulfur from the former comes into contact with the iron from the latter. The alkaline conditions in the white favor the stripping of sulfur atoms from the alb.u.men proteins when heat unfolds them, and the sulfur reacts with iron in the surface layer of yolk to form ferrous sulfide. The older the egg, the more alkaline the white, and the more rapidly this reaction occurs. High temperatures and prolonged cooking produce more ferrous sulfide. The occasional green-gray discoloration on the surface of hard-cooked yolks is a harmless compound of iron and sulfur, ferrous sulfide. It forms at the interface of white and yolk because that's where reactive sulfur from the former comes into contact with the iron from the latter. The alkaline conditions in the white favor the stripping of sulfur atoms from the alb.u.men proteins when heat unfolds them, and the sulfur reacts with iron in the surface layer of yolk to form ferrous sulfide. The older the egg, the more alkaline the white, and the more rapidly this reaction occurs. High temperatures and prolonged cooking produce more ferrous sulfide.

Yolk greening can be minimized by using fresh eggs, by cooking them as briefly as possible, and by cooling them rapidly after cooking.

Long-Cooked Eggs An intriguing alternative to the standard hard-cooked egg is the Middle Eastern An intriguing alternative to the standard hard-cooked egg is the Middle Eastern hamindas hamindas (Hebrew) or (Hebrew) or beid hamine beid hamine (Arabic), which are cooked for anywhere from 6 to 18 hours. They derive from the Sephardic Sabbath mixed stew (called (Arabic), which are cooked for anywhere from 6 to 18 hours. They derive from the Sephardic Sabbath mixed stew (called hamin, hamin, from the Hebrew for "hot"), which was put together on Friday, cooked slowly in the oven overnight, and served as a midday Sabbath meal. Eggs included in the stew sh.e.l.l and all, or alternatively long-simmered in water, come out with a stronger flavor and a striking, tan-colored white. During prolonged heating in alkaline conditions, the quarter-gram of glucose sugar in the white reacts with alb.u.men protein to generate flavors and pigments typical of browned foods (see the explanation of the Maillard reaction on p. 778). The white will be very tender and the yolk creamy if the cooking temperature is kept in a very narrow range, between 160 and 165F/7174C. from the Hebrew for "hot"), which was put together on Friday, cooked slowly in the oven overnight, and served as a midday Sabbath meal. Eggs included in the stew sh.e.l.l and all, or alternatively long-simmered in water, come out with a stronger flavor and a striking, tan-colored white. During prolonged heating in alkaline conditions, the quarter-gram of glucose sugar in the white reacts with alb.u.men protein to generate flavors and pigments typical of browned foods (see the explanation of the Maillard reaction on p. 778). The white will be very tender and the yolk creamy if the cooking temperature is kept in a very narrow range, between 160 and 165F/7174C.

Eggs Cooked Out of the Sh.e.l.l Baked, Shirred, en Cocotte There are several ways of soft-cooking eggs that are broken out of the sh.e.l.l and into a container, which might be a dish or a hollowed-out fruit or vegetable. As is true of in-sh.e.l.l soft-cooked eggs, timing is of the essence to avoid overcoagulation of the white and yolk proteins, and depends on the nature and placement of the heat source. In the case of baked or shirred eggs, the dish should be set on the middle rack to avoid overcooking the top or bottom while the rest cooks through. Eggs There are several ways of soft-cooking eggs that are broken out of the sh.e.l.l and into a container, which might be a dish or a hollowed-out fruit or vegetable. As is true of in-sh.e.l.l soft-cooked eggs, timing is of the essence to avoid overcoagulation of the white and yolk proteins, and depends on the nature and placement of the heat source. In the case of baked or shirred eggs, the dish should be set on the middle rack to avoid overcooking the top or bottom while the rest cooks through. Eggs en cocotte en cocotte ("in the ca.s.serole") are cooked in dishes set in a pan of simmering water, either on the stovetop or in the oven. Here the eggs are well buffered from the heat source, yet cook just as quickly as baked eggs because water transfers heat more rapidly than the oven air. ("in the ca.s.serole") are cooked in dishes set in a pan of simmering water, either on the stovetop or in the oven. Here the eggs are well buffered from the heat source, yet cook just as quickly as baked eggs because water transfers heat more rapidly than the oven air.

Eggs and FireAnother Way with Eggs (Roasting)Turn fresh eggs carefully in warm ashes near the fire so that they cook on all sides. When they begin to leak they are thought to be freshly done, and so are served to guests. These are the best and are most agreeably served.Eggs on a SpitPierce eggs lengthwise with a well-heated spit and parch them over the fire as if they were meat. They should be eaten hot. This is a stupid invention and unsuitable and a cooks' joke.- Platina, De honesta voluptate et valetudine, De honesta voluptate et valetudine, 1475 1475 Poached Eggs A poached egg is a containerless, soft-cooked egg that generates its own skin of coagulated protein in the first moments of cooking. Slid raw into a pan of already simmering water - or cream, milk, wine, stock, soup, sauce, or b.u.t.ter - it cooks for three to five minutes, until the white has set, but before the yolk does. A poached egg is a containerless, soft-cooked egg that generates its own skin of coagulated protein in the first moments of cooking. Slid raw into a pan of already simmering water - or cream, milk, wine, stock, soup, sauce, or b.u.t.ter - it cooks for three to five minutes, until the white has set, but before the yolk does.

The Problem of Untidy Whites The tricky thing about poached eggs is getting them to set into a smooth, compact shape. Usually the outer layer of thin white spreads irregularly before it solidifies. It's helpful to use fresh Grade AA eggs sh.e.l.led just before cooking, which have the largest proportion of thick white and will spread the least, and water close to but not at the boil, which will coagulate the outer white as quickly as possible without turbulence that would tease the thin alb.u.men all over the pan. Other conventional cookbook tips are not very effective. Adding salt and vinegar to the cooking water, for example, does speed coagulation, but it also produces shreds and an irregular film over the egg surface. An unconventional but effective way to improve the appearance of poached eggs is simply to remove the runny white from the egg The tricky thing about poached eggs is getting them to set into a smooth, compact shape. Usually the outer layer of thin white spreads irregularly before it solidifies. It's helpful to use fresh Grade AA eggs sh.e.l.led just before cooking, which have the largest proportion of thick white and will spread the least, and water close to but not at the boil, which will coagulate the outer white as quickly as possible without turbulence that would tease the thin alb.u.men all over the pan. Other conventional cookbook tips are not very effective. Adding salt and vinegar to the cooking water, for example, does speed coagulation, but it also produces shreds and an irregular film over the egg surface. An unconventional but effective way to improve the appearance of poached eggs is simply to remove the runny white from the egg before before poaching. Crack the egg into a dish, then slide it into a large perforated spoon and let the thin white drain away for a few seconds before sliding the egg into the pan. poaching. Crack the egg into a dish, then slide it into a large perforated spoon and let the thin white drain away for a few seconds before sliding the egg into the pan.

Timing Poached Eggs by Levitation There's a professional method for poaching eggs that also makes great amateur entertainment. This is the restaurant technique in which eggs are cracked into boiling water in a tall stockpot, disappear into the depths, and - as if by magic! - bob up to the surface again just when they're done: a handy way indeed to keep track of many eggs being cooked at once. The trick is the use of vinegar and salt (at about and 1 tablespoon respectively for each quart of cooking water, 8 and 15g per liter) and keeping the water at the boil. The vinegar reacts with bicarbonate in the thin white to form tiny buoyant bubbles of carbon dioxide, which get trapped at the egg surface as its proteins coagulate. The salt increases the density of the cooking liquid just enough that the egg and three minutes' worth of bubbles will float. There's a professional method for poaching eggs that also makes great amateur entertainment. This is the restaurant technique in which eggs are cracked into boiling water in a tall stockpot, disappear into the depths, and - as if by magic! - bob up to the surface again just when they're done: a handy way indeed to keep track of many eggs being cooked at once. The trick is the use of vinegar and salt (at about and 1 tablespoon respectively for each quart of cooking water, 8 and 15g per liter) and keeping the water at the boil. The vinegar reacts with bicarbonate in the thin white to form tiny buoyant bubbles of carbon dioxide, which get trapped at the egg surface as its proteins coagulate. The salt increases the density of the cooking liquid just enough that the egg and three minutes' worth of bubbles will float.

Fried Eggs The containerless fried egg is even more p.r.o.ne to spreading than the poached egg because it is heated only from below, so its white is slower to coagulate. Fresh, high-grade eggs give the most compact shape, and straining off the thin white also helps. The ideal pan temperature for a pale, tender fried egg is around 250F/ 120C, when b.u.t.ter has finished sizzling but hasn't yet browned, or oil to which a drop of water has been added has stopped sputtering. At higher temperatures, you lose tenderness but gain a more flavorsome, browned and crisp surface. The top of the egg can be cooked by turning the egg over after a minute or so, or by adding a teaspoon of water to the pan and covering it to trap the resulting steam, or - as in the browned Chinese "coin-purse" egg - the egg can be folded over onto itself when barely set, so that top and bottom are crisped but the yolk remains protected and creamy. The containerless fried egg is even more p.r.o.ne to spreading than the poached egg because it is heated only from below, so its white is slower to coagulate. Fresh, high-grade eggs give the most compact shape, and straining off the thin white also helps. The ideal pan temperature for a pale, tender fried egg is around 250F/ 120C, when b.u.t.ter has finished sizzling but hasn't yet browned, or oil to which a drop of water has been added has stopped sputtering. At higher temperatures, you lose tenderness but gain a more flavorsome, browned and crisp surface. The top of the egg can be cooked by turning the egg over after a minute or so, or by adding a teaspoon of water to the pan and covering it to trap the resulting steam, or - as in the browned Chinese "coin-purse" egg - the egg can be folded over onto itself when barely set, so that top and bottom are crisped but the yolk remains protected and creamy.

Poached ThreadsA kind of poached egg that was enjoyed in 17th century France and England, and still is in modern China and Portugal, is egg yolk trailed in a thin stream into hot syrup, then lifted out as sweet, delicate threads.

Scrambled Eggs Scrambled eggs and omelets are made from yolks and whites mixed together, and are therefore a good fate for fragile, runny lower-quality eggs. These dishes frequently include other ingredients. Cream, b.u.t.ter, milk, water, or oil (used in China) will dilute the egg proteins and produce a tenderer ma.s.s when the eggs are carefully cooked; overheating, however, will cause some of the added liquid to separate. Watery vegetables like mushrooms should be precooked to prevent them from weeping into the eggs. Chopped herbs, vegetables, or meats should be warm - not hot or cold - to avoid uneven heating of adjacent egg proteins. Scrambled eggs and omelets are made from yolks and whites mixed together, and are therefore a good fate for fragile, runny lower-quality eggs. These dishes frequently include other ingredients. Cream, b.u.t.ter, milk, water, or oil (used in China) will dilute the egg proteins and produce a tenderer ma.s.s when the eggs are carefully cooked; overheating, however, will cause some of the added liquid to separate. Watery vegetables like mushrooms should be precooked to prevent them from weeping into the eggs. Chopped herbs, vegetables, or meats should be warm - not hot or cold - to avoid uneven heating of adjacent egg proteins.

The Key to Scrambled Eggs: Slow Cooking Scrambled eggs made in the usual quick, offhand way are usually hard and forgettable. The key to moist scrambled eggs is low heat and patience; they will take several minutes to cook. The eggs should be added to the pan just as b.u.t.ter begins to bubble, or oil makes a water drop dance gently. Texture is determined by how and when the eggs are disturbed. Large, irregular curds result if the cook lets the bottom layer set for some time before sc.r.a.ping to distribute the heat. Constant sc.r.a.ping and stirring prevents the egg proteins at the bottom from setting into a separate, firm layer, and produces a creamy, even ma.s.s of yolk and thin white punctuated with very fine curds of thick white. Scrambled eggs should be removed from the pan while still slightly underdone, since they will continue to thicken for some time with their residual heat. Scrambled eggs made in the usual quick, offhand way are usually hard and forgettable. The key to moist scrambled eggs is low heat and patience; they will take several minutes to cook. The eggs should be added to the pan just as b.u.t.ter begins to bubble, or oil makes a water drop dance gently. Texture is determined by how and when the eggs are disturbed. Large, irregular curds result if the cook lets the bottom layer set for some time before sc.r.a.ping to distribute the heat. Constant sc.r.a.ping and stirring prevents the egg proteins at the bottom from setting into a separate, firm layer, and produces a creamy, even ma.s.s of yolk and thin white punctuated with very fine curds of thick white. Scrambled eggs should be removed from the pan while still slightly underdone, since they will continue to thicken for some time with their residual heat.

Omelets If good scrambled eggs demand patience, a good omelet takes panache - a two- or three-egg omelet cooks in less than a minute. Escoffier described the omelet as scrambled eggs held together in a coagulated envelope, a skin of egg heated past the moist, tender stage to the dry and tough, so that it has the strength to contain and shape the rest. Its formation requires a hotter pan than do evenly tender scrambled eggs. But a hot pan means fast cooking to avoid overcooking. If good scrambled eggs demand patience, a good omelet takes panache - a two- or three-egg omelet cooks in less than a minute. Escoffier described the omelet as scrambled eggs held together in a coagulated envelope, a skin of egg heated past the moist, tender stage to the dry and tough, so that it has the strength to contain and shape the rest. Its formation requires a hotter pan than do evenly tender scrambled eggs. But a hot pan means fast cooking to avoid overcooking.

An important key to a successful omelet is contained in the name of the dish, which since the Middle Ages has gone through various forms - alemette, homelaicte, omelette alemette, homelaicte, omelette (the standard French) - and comes ultimately from the Latin (the standard French) - and comes ultimately from the Latin lamella, lamella, "thin plate." The volume of eggs and the pan diameter should be balanced so that the mix forms a relatively "thin plate." The volume of eggs and the pan diameter should be balanced so that the mix forms a relatively thin thin layer; otherwise the scrambled ma.s.s will take too long to cook and be hard to hold together. The usual recommendation is three eggs in a medium-sized frying pan, which should have a well-seasoned or nonstick surface so that the skin will come away from it cleanly. layer; otherwise the scrambled ma.s.s will take too long to cook and be hard to hold together. The usual recommendation is three eggs in a medium-sized frying pan, which should have a well-seasoned or nonstick surface so that the skin will come away from it cleanly.

Safe Poached EggsThe runny yolk in ordinary poached eggs hasn't been heated enough to eliminate any salmonella bacteria that might be present. To eliminate bacteria while keeping the yolk soft, transfer the finished egg to a second large pan full of water at 150F/65C, cover, and let sit for 15 minutes. Check the thermometer every few minutes; if the water drops below 145F/63C, put it back on the heat. If you want to cook the eggs a short time before serving them, this hot-water bath is a useful alternative to chilling and then reheating.

The skin of an omelet can be formed either just at the end of the cooking, or right from the beginning. The fastest technique is to scramble the eggs vigorously with a spoon or fork in a hot pan until they begin to set, then push the curds into a rough disk, let the bottom consolidate for a few seconds, shake the pan to release the disk, and fold it onto itself. A more substantial and more uniform-looking skin results if the eggs are left undisturbed for a while to allow the bottom surface to set. The pan is then shaken periodically to free the skin from the pan while the still-liquid portion alone is stirred until creamy, and the disk finally folded and slipped onto a plate. Yet another way is to let the bottom of the mix set, then lift an edge with the fork and tip the pan to let more of the liquid egg run underneath. This is repeated until the top is no longer runny, and the ma.s.s then folded over.

An omelet with an especially light texture (omelette soufflee) is made by whipping the eggs until they're full of bubbles, or by whipping the separated whites into a foam and folding them gently back into the mixture of yolks and flavorings. The mix is poured into a heated pan and cooked in a moderate oven.

Egg-Liquid Mixtures: Custards and Creams Definitions Eggs are mixed with other liquids across a tremendous range of proportions. One tablespoon of cream will enrich a scrambled egg, while one beaten egg will slightly thicken a pint of milk into an eggnog. Just about in the middle of this range - at around 4 parts liquid to 1 part egg, or 1 cup/250 ml to 1 or 2 eggs - are the custards and creams, dishes in which the egg proteins give substantial body to otherwise thin liquids. These terms are often used interchangeably, which obscures a useful distinction.

In this section I'll use custard custard to mean a dish prepared and served in the same container, often baked and therefore unstirred, so that it sets into a solid gel. The custard family includes savory quiches and timbales as well as sweet flans, cremes caramels, pots de creme, cremes brulees, and cheesecakes. to mean a dish prepared and served in the same container, often baked and therefore unstirred, so that it sets into a solid gel. The custard family includes savory quiches and timbales as well as sweet flans, cremes caramels, pots de creme, cremes brulees, and cheesecakes. Creams, Creams, by contrast, are auxiliary preparations, made from essentially the same mix as custards but stirred continuously during stovetop cooking to produce a thickened but malleable, even pourable ma.s.s. Pastry cooks in particular use creme anglaise (so-called "custard cream"), pastry cream (creme patissiere), and their relatives to coat or fill or underlie a great variety of baked sweets. by contrast, are auxiliary preparations, made from essentially the same mix as custards but stirred continuously during stovetop cooking to produce a thickened but malleable, even pourable ma.s.s. Pastry cooks in particular use creme anglaise (so-called "custard cream"), pastry cream (creme patissiere), and their relatives to coat or fill or underlie a great variety of baked sweets.

Cla.s.sically Smooth Scrambled EggsOeufs brouilles au jus (Scrambled Eggs with Meat Demiglace) (Scrambled Eggs with Meat Demiglace)Break a dozen fresh eggs into a dish, beat them thoroughly, pa.s.s them through a strainer into a ca.s.ser