Types of Eggs
Chicken Eggs | Other Types of Eggs
Since chicken eggs are the predominate variety used in cooking, all of the information presented in terms of preparation, cooking, nutrition, and products refers to eggs from chickens except where noted.
Types of Chicken Eggs
Standard or commercially produced chicken eggs are used more often than any other type of chicken egg and are the eggs most commonly found in food stores. Chicken eggs with white shells make up the bulk of the eggs sold in food stores, but sometimes eggs with brown shells are available, especially in farmers markets. The color of the shell is determined by the breed of the hen. The only difference between white and brown eggs is the color - there is no difference in flavor or nutritional value.
Fertile eggs are simply eggs that can be incubated and developed into chicks. They have often been thought of as being more nutritious than non-fertile eggs, but this is not the case. There is no difference in the nutrient value between the two. Fertile eggs have higher production costs so they are more expensive for the consumer and they also spoil more quickly than non-fertile eggs.
Organic eggs are produced from hens that have been given feed in which all of the ingredients were grown without the aid of commercial fertilizers, pesticides, or herbicides. This makes the cost of production more expensive which makes the price of organic eggs higher than non-organic. As far as nutrition is concerned, organic eggs are no different than non-organic eggs.
Free-range is the name given to eggs produced by hens that have been raised outdoors, however, because of climate, most hens are not raised entirely in the open. For this reason, eggs may be called free-range if the hens have daily access to the outdoors, but may not actually spend that much time outdoors. The nutrient content is the same for free-range eggs as it is with eggs produced from confined hens. The cost of a free-range egg is higher because of additional costs encountered by free-range egg producers.
Other Types of Eggs
There are other types of eggs, such as quail, duck, goose, turkey, and ostrich, that are used, but not nearly as often as chicken eggs. An important point to remember about egg varieties other than chicken is that they are more apt to contain harmful bacteria, so they should always be well cooked.
Other Types of Eggs
Quail Eggs are much smaller than chicken eggs, but the flavor is similar. Five quail eggs are equal to one chicken egg. The shells are speckled and range in color from dark brown to blue or white. Quail eggs are often hard-boiled and served as an hors d’oeuvre, garnish, or accompaniment for salads.
Duck Eggs are slightly larger than chicken eggs. The chalaza in a duck egg is not as noticeable as it is in a chicken egg and the white is more transparent with less yellow coloring. They have more flavor than chicken eggs, but they also have a higher fat content and more cholesterol. The egg white has a greater level of albumen (the protein of the egg white) than a chicken egg. Because of their richness and gelatinous properties, duck eggs are well suited for dessert recipes. The duck eggs that are usually available to consumers are quite large, but producers sell duck eggs in sizes ranging from very small to jumbo.
Goose Eggs are much larger than chicken or duck eggs. They have more flavor than chicken eggs, are very rich, and like duck eggs, are best used in dessert dishes. Goose eggs are extremely high in cholesterol (over 1200 mg. per egg) and fat, so they should be used sparingly.
Turkey Eggs are similar to chicken eggs, but are larger and have white to cream colored shells with brown speckles. They are approximately 1Â½ times larger than a jumbo chicken egg and are very high in cholesterol and fat, but the flavor is very similar. Turkey eggs are rarely available to the consumer because most of the eggs are used for hatching more turkeys, but they are sometimes available in specialty markets.
Ostrich Eggs are hard to find, but one egg goes a long way. One ostrich egg is equal to 20 to 24 large chicken eggs. They are mainly sold for novelty value and one egg can be made into several large omelets or it can be scrambled.
It is often necessary to separate egg whites and yolks for many recipes. Beaten egg whites are used in many baked items and desserts such as meringues, cakes, and soufflÃ©s, providing air and volume to the dish. Yolks are required for sauces such as hollandaise and mayonnaise and for sweet items such as butter cream frosting and custards. It is important to learn proper methods for separating eggs successfully.
The traditional method for separating eggs is to break the egg over a bowl, splitting the shell into halves, and then passing the contents of the egg from one half of the shell to the other half. This allows the white to fall into the bowl as the yolk is transferred back and forth between the shell halves.
It is best to use three bowls for this method: one to catch the white as the egg is being separated, one to store the separated whites, and one to store the separated yolks. As the egg is being passed between the shell halves, make sure the yolk does not break and spill into the bowl containing the white. Once all of the white has fallen into the bowl, the yolk can be placed into a different bowl to store the yolks. It is also important to transfer the white to a different bowl before separating the next egg. When separating several eggs, you don’t want to risk dropping any yolk into the bowl of already separated whites. If this happens, it can be difficult to remove the portion of yolk from the bowl of whites. Since most recipes requiring beaten egg whites will be negatively affected by the presence of any yolk, you may have to start over and waste the egg whites that have already been separated.
One negative aspect of the traditional egg separating method is the possibility that the contents of the egg may become contaminated during the procedure. When the egg is passed back and forth between the shell halves, it may become contaminated if bacteria are present on the shell. Bacteria may be present on the shell even after it is sanitized and the shell may also become contaminated from other food sources that it may come in contact with.
A second method that may be used for separating the white and the yolk is to insert a needle into one end of the egg, creating a hole that can be enlarged by moving the needle in a circular direction. The egg white should drain through the hole, leaving the yolk behind. The egg shell can then be cracked open to remove the unbroken yolk.
While this method may be easy to do, it can take awhile for the egg white to drain from the shell. There is also a slight possibility that this method may transfer germs existing on the shell to the contents of the egg.
A third method of separating the white and the yolk is the funnel method. Place a small funnel over a container and crack the egg over the funnel. Be careful not to break the yolk. The egg white should slide through the funnel opening into the container, leaving the yolk behind. The yolk and the whites are then transferred to other containers. Make sure that the funnel opening is small enough so that the yolk does not slide through yet large enough so that the whites can slide through easily. This method is more sanitary because the contents of the egg have very little contact with the outside of the shell.
Separator Tool Method
Perhaps the easiest and most sanitary egg separation method is with the use of an egg separating tool. It is basically a tray which is centered in a circular frame with slots around the perimeter. When the egg is broken over the separator, the yolk slides into the center tray while the white falls through the slots in the frame and into a container placed beneath the separator. The tools come in different styles, are usually constructed of plastic or metal, and are inexpensive.
Beating Egg Whites | Beating Egg Yolks
Beating Egg Whites
Egg whites that are correctly beaten may increase in volume by up to 8 times. They should be extremely smooth and firm, but not dry, forming stiff peaks. They can be beaten by hand or with an electric mixer. A copper bowl is often used, especially by professional chefs. The slight acidity of the copper results in a chemical reaction with the egg whites which helps to stabilize them. If copper is not available, the next best choice is stainless steel. A pinch of cream of tartar per egg white can be added as a stabilizer, replacing the acidic properties of the copper. A balloon whip or large wire whisk may be used to beat the egg whites by hand. It is extremely important that the bowl and whisk be very clean and dry and that no trace of oil is present. Egg whites will not increase to the desired volume if contaminated with any trace of oil. This is also true if any yolk is present in the egg whites. Plastic bowls and utensils should never be used because plastic tends to hold some oil even after thorough cleaning.
Whole eggs may be separated into whites and yolks immediately after removal from the refrigerator, but the whites should be allowed to reach room temperature before beating because this allows the egg whites to increase in volume more rapidly when beaten. However, the egg whites should not remain without refrigeration for more than 2 hours, which includes the preparation time, in order to reduce the possibility of bacterial growth. Egg whites may also be warmed more quickly by placing the bowl of whites over warm water. Egg whites cannot achieve their full volume on humid days.
Steps For Hand Beaten Egg Whites
Add a pinch of cream of tartar per egg white or about Â¼ teaspoon for every 4 egg whites. This will help to stabilize the egg whites and prevent them from losing their volume after the beating has stopped. Cream of tartar does not need to be added if a copper bowl is used.
Start slowly, using a circular motion at about 2 strokes per second. When the egg whites begin to foam, usually after 30 seconds or so, increase the speed to about 4 strokes per second. The idea is to get as much air into the egg whites as possible and to keep them in constant motion.
After 2 to 3 minutes of vigorous beating, the egg whites will increase in volume.
After another 2 minutes or so, the egg whites should reach their maximum volume.
You can test beaten egg whites for the proper volume, regardless if they are manually beaten or beaten with a machine. Pull some from the bowl on the end of a whisk or spoon to see if the egg whites form soft peaks. You should be able to hold the whisk or spoon upside down and the egg whites will not fall off. If the egg whites fall off, continue beating. Don’t over beat the egg whites because they will begin to break down and will not blend properly with other ingredients.
Egg Whites Beaten with an Electric Mixer
A hand held electric mixer also works well for beating egg whites, because it allows you the freedom of moving the spinning beaters all around the bowl, keeping the egg whites in motion. A stationary mixer in which the beater spins as well as rotates around the circumference of the bowl, is an excellent tool and eliminates all of the manual work. Some stationary models have beaters that do not move around the circumference of the bowl, but have bowl that slowly spins on a stand as the beaters spin. Kitchen tools such as blenders and food processors should not be used for beating egg whites.
When using any electric mixer, start at a slow speed and continue for about 60 seconds. As with manual beating, cream of tartar is added to the egg whites for stabilization of the beaten whites. Gradually increase the speed until the egg whites reach their full volume. Operating the mixer at a high speed from the start will not allow the egg whites to reach their full volume. The entire beating process usually takes no more than 3 minutes with the better quality electric mixers.
The beaten egg whites should be folded immediately into any other ingredients used in the selected recipe. It is a good idea to have the other ingredients prepared first and then beat the egg whites as the final step so that they will not have time to break down and lose volume.
Beating Egg Yolks
Egg yolks that will be used for the preparation of desserts are often required to be blended with sugar and beaten until the mixture reaches the “ribbon” stage. This helps to prevent the yolks from becoming granular when heat is applied. When some of the egg yolk and sugar mixture is lifted with a beater or spoon and falls back into the bowl forming a slowly disappearing ribbon on the surface, the ribbon stage has been reached. The egg yolks and sugar can be beaten by hand using a whisk or they can be beaten using an electric mixer.
Add the required number of egg yolks (depending on the recipe) to a stainless steel or glass bowl and begin to lightly beat the yolks.
Add a small quantity of the sugar (the quantity depends on the recipe and the number of yolks used) and continue beating, but more vigorously. While beating the mixture, gradually add the remaining sugar. The mixture will become thicker and the color will lighten.
Continue beating until the ribbon stage is reached (approximately 3 minutes from start to finish when using a whisk), but do not over beat or the egg yolks may become granular. The mixture will be thick and the color will be pale yellow. The mixture will form a ribbon on the surface when some of it falls onto the surface from a whisk, a spoon, or electric beaters.
Cooking and Beating
For some recipes, egg yolks may need to be cooked as they are beaten. This is true of hollandaise sauce, which is an egg yolk and butter sauce flavored with lemon juice and pepper. When preparing hollandaise sauce, make sure everything that is needed is within arms reach because once the process has begun, the beating of the egg yolks cannot stop.
Place the egg yolks in a small saucepan (which is not heated) and add one tablespoon of cold water per yolk.
Whisk the egg yolks and water (off the heat) for about 45 to 60 seconds and then place the pan over low heat and continue to whisk rapidly. The eggs must heat slowly or they may become granular. If the heat is too high, the yolks will scramble. It is important to keep the egg yolks in constant motion.
A sink or large bowl of ice water should be nearby so that if the egg yolks start to become too warm, the pan can be plunged into the cold water to stop the cooking. When the egg yolks are smooth and have increased in volume (as shown in the picture on the right), remove the pan from the heat. You should be able to briefly see the bottom of the pan between strokes of the whisk.
While whisking continuously, slowly add clarified butter or softened whole butter. (Make sure the clarified butter is not too warm.) Whisk in small quantities of butter at a time. The sauce will not thicken if too much butter is added right away. One large egg yolk is able to absorb as much as 3 ounces of butter, but it is safer to use less than this (2 ounces per yolk is suitable) to make sure that the yolks absorb all of the butter.
Using clarified butter makes the hollandaise sauce thicker while using whole butter, which contains milk solids and water, makes a thinner sauce. A thin sauce is appropriate for use on light recipes of fish and seafood or asparagus and a thick sauce is best for serving on eggs Benedict or steak.
To finish the sauce, slowly add some lemon juice while whisking and then add some salt and white or black pepper to taste.
There are several variations of hollandaise sauce that can be prepared. All of the variations are made exactly like hollandaise except that the flavorings used to finish the sauces are different for each one.
* BÃ©arnaise Sauce: flavored with tarragon, shallots, pepper, and wine. * Choron Sauce: flavored the same as bÃ©arnaise with the addition of tomato paste. * Colbert Sauce: the same as bÃ©arnaise except it is also flavored with meat glaze. * Chantilly Sauce: whipped cream folded into the hollandaise sauce. * Vin Blanc Sauce: hollandaise sauce flavored with white wine fish stock. * Maltaise Sauce: hollandaise flavored with orange juice (in addition to the lemon juice).
Using the term “boiled” when referring to cooking eggs in the shell can be misleading, because eggs referred to as “hard-boiled” or “soft-boiled” should never be cooked at a full boil for the entire length of the cooking time. Eggs cooked in the shell with heat that is too high or with a cooking time that is too lengthy, will become tough and rubbery and a dark line may form between the yolk and the white.
The following steps can be used for cooking eggs in the shell:
Pierce the large end of the eggs with a pin or needle. This pierces the air cell, allowing the air to escape, preventing a flat spot from being formed on the large end of the egg during the cooking process. It also helps in making the eggs easier to peel after cooking.
Pour cold water into a saucepan and add 1Â½ teaspoons of salt per quart of water. (The salt may help make the peeling process easier). Make sure there is enough water in the pan so that the eggs will be completely covered. Bring the water to a boil and with a large spoon, place the eggs in a single layer on the bottom of the pan.
When the water returns to a boil, turn down the heat so that the water is at a low simmer and then begin timing the eggs for the desired doneness. Do not cover the pan.
Use the following cooking times as a guide for the desired
firmness for the yolk of each egg size (the whites will be firm).
Size Degree of Doneness Time Required
Medium Soft-cooked yolk 4 minutes
Medium-cooked yolk 6 minutes
Hard-cooked yolk 11 minutes
Large Soft-cooked yolk 5 minutes
Medium-cooked yolk 7 minutes
Hard-cooked yolk 12 minutes
Extra Large Soft-cooked yolk 6 minutes
Medium-cooked yolk 8 minutes
Hard-cooked yolk 13 minutes
Note: The temperature of the egg at the start of the cooking process will affect the cooking time. An egg that is at room temperature at the start of the cooking process will require about 1 minute less cooking time for each time listed above. The times listed above are based on eggs taken directly from the refrigerator.
After the required time has elapsed, run cold water over the eggs to stop the cooking process. This will help prevent discoloration of the yolk and will also assist with the peeling process. Running cold water over the eggs creates steam between the egg white and the shell which makes the shell easier to remove.
To peel the egg, simply roll it lightly over a hard surface which will crack the shell, making it easy to remove. It is also worth noting that very fresh eggs are more difficult to peel than older eggs.
Hard-cooked eggs can be served whole or they may be cut and sliced. An egg slicer can be used to prepare evenly sliced sections that can be used in salads or as a garnish. The egg slicer is a tool that consists of a tray hinged to a cutter that has a series of wires. The egg is placed on its side in the tray and the cutter is closed down over the egg, producing slices of equal thickness. The egg can be rotated and sliced a second and third time in order to chop the egg.
An egg wedger may also be used and is similar to the slicer in design except that the egg sits upright instead of on its side. The cutting tool produces equal wedges instead of slices. The wedger can also be used to cut only the top portion of the egg to create a decorative design and to produce a cavity at the top which can be filled with other ingredients.
Hard-cooked eggs can also be cut in half the long way so that the solid yolk can be removed from the two halves. The yolk is then blended with other ingredients such as mayonnaise, mustard, and seasonings and the mixture is stuffed back into the yolk cavity of the egg halves and served. This is known as stuffed eggs or deviled eggs.
A coddled egg is cooked more slowly than a boiled egg, but basically yields the same results, except that the egg is a bit more tender. The following steps can be used for coddling eggs:
Pierce the large end of the eggs with a pin. This pierces the air cell, allowing the air to escape, preventing a flat spot from being formed on the large end of the egg during the cooking process. It also helps in making the eggs easier to peel after cooking.
Add cold water and 1Â½ teaspoons of salt per quart of water in a saucepan. Make sure there is enough water in the pan so that the eggs will be completely covered. Place the eggs in a single layer in the saucepan and leave the pan uncovered.
Place the pan on medium heat and bring the water to a simmer, but not to a full boil. Remove the pan from the heat and cover it. The length of time that the eggs remain in the covered pan determines the degree of firmness of the yolk.:
* Soft yolk: 4 to 6 minutes * Medium yolk: 6 to 8 minutes * Hard yolk: 20 to 25 minutes
Note: When coddling eggs, the size of the egg and its temperature at the start of the cooking process will have an affect on the cooking time. An extra large egg used directly from the refrigerator will require the full cooking time as stated above and a medium egg that has been brought up to room temperature before cooking will require only the minimum time listed.
To stop the cooking process, run cold water over the eggs. It is best to use older eggs for coddling because they peel easier. Soft-cooked coddled eggs are often served in an egg cup and eaten directly from the shell because they are difficult to peel.
Another method used for coddling eggs involves the use of a special porcelain dish with a screw top. The egg, without the shell, is placed in the dish, the cover is screwed on, and the dish is placed in a pan of heated water. When the cooking process is complete, the dish is removed from the water and is used to serve the egg.
A poached egg cooked on the stovetop is one that is cooked in simmering water without the shell. Unlike a boiled or coddled egg that benefits from the use of an older egg, a poached egg is best when a very fresh egg is used. This is because the fresh egg, when placed into the heated water, will not spread out like an older egg, yielding better results with the shape and texture of the egg. If an older egg must be used, it can be simmered in the shell for a few seconds so that the white is just slightly congealed. When the egg is broken into the simmering water, it will not spread out as much. One tablespoon of vinegar added to the water will also help with coagulating the white to keep it from spreading too much.
The following steps can be used for poaching eggs:
Pierce the large end of the eggs with a pin.
Add cold water to a large saucepan and bring the water to a boil. With a slotted spoon, lower the eggs into the boiling water for no more than 10 seconds. This helps to slightly set the whites so that they do not spread out as much when the eggs are poached.
Add 1 tablespoon of vinegar to the boiling water and then turn down the heat so that the water is simmering.
It is best to open the egg shell as close to the surface of the simmering water as possible so that the egg will spread out less.
The poaching process should be timed for about 4 minutes. Remove the eggs from the water with a large slotted spoon in the order in which they entered the water. This allows the last egg to be cooked the same amount of time as the first. Wait a few seconds between the removal of each egg. Each egg can be bathed in warm water to remove any trace of the vinegar. The egg white should be firm, but the yolk should remain liquid. If there are any streamers of egg white extending out from the main portion of the egg, they can be trimmed off before serving.
Another method for poaching eggs involves a metal egg poaching form which makes the process almost foolproof. The metal form is a shallow, oval, slotted container with an attached handle. The egg is broken into the form which is then lowered into simmering water. The metal form or poacher is convenient to use and creates a pleasing shape. Using fresh eggs or older eggs is less of a concern when using the metal poacher.
Regardless of how the eggs are poached, the water should be at a simmer and not a full boil. If metal poaching tools are used, several can be placed in the pan at one time. If the forms are not used, several eggs can also be poached at one time, but more care must be taken when breaking the eggs over the water so that each egg has its own space in the pan.
If the egg is to be poached in a microwave, there are various poaching dishes that can be used.
Crack the egg into the dish and then poke the yoke and white with a toothpick several times to reduce the tendency for it to burst while cooking. The egg will also burst or explode if the cooking time or heat is too excessive. Cover the dish securely with a plastic food wrap. Realizing that different microwave wattages and cooking at different altitudes will affect the cooking time, it will be necessary to experiment in order to achieve the best results, allowing a little longer or a little less time for the desired hardness. When cooking only one egg, as a general rule for average elevations of 1,000 feet, set the desired time around 40 seconds at a medium cooking power for the first stage of cooking. A time of 40 seconds for a medium size egg and 45 seconds for a large egg will usually give it a soft consistency. After cooking the egg for the first phase, allow it to remain covered in the cup, in the microwave for 15 seconds or so and reset the microwave for 10 to 15 seconds at a medium power level. Cooking the egg in two phases allows the egg to cook slowly, moving from a soft poached egg to a hard poached egg if desired by adding a few more seconds and letting it stand slightly longer either between or after the cooking phases. If the egg yolk or white explodes, reduce the time for the phase causing the reaction. Also, consider cooking the egg in three phases, each one with a decreased amount of time to succeed with a perfect result. Achieving the desired results can be accomplished by doing some testing and watching the egg during the final cooking stage. Since all microwaves differ in cooking power and corresponding temperatures, test the results several different ways to determine which is best for the desired results or hardness.
Frying is another popular method of cooking eggs and it is easy to do. Butter or cooking fat is heated in the bottom of the pan. Whole eggs are cracked and opened over the pan. The eggs should be opened as close to the bottom of the pan as possible so that they maintain a pleasing shape and do not spread out too much. The eggs are cooked until the whites are firm and the yolk is runny or firm, depending on how they are desired.
There are several methods used to finish cooking the eggs. They can be left unturned and can be basted with the hot fat. A few drops of water can be added and the pan can be covered to steam cook the eggs. The eggs can also be finished by carefully turning them over using a spatula once they have firmed up on the bottom. The eggs are then cooked until the yolks are at a desired doneness, such as over easy (runny yolk), over medium (soft yolk), or over hard (firm yolk).
Scrambling is a method of preparing an egg in which the white and the yolk are blended together and cooked in a sautÃ© pan.
Several eggs are stirred slightly in a bowl to blend the whites and the yolks. Salt and pepper can be added to the eggs or added when the eggs are served.
Butter is dropped in a metal or nonstick sautÃ© pan that has been placed on moderately high heat. The butter should foam and bubble, but not turn brown.
The eggs are poured into the heated pan.
The eggs are then stirred, scraped from the bottom of the pan, and turned during the cooking process.
As the eggs begin to congeal, they begin to cook very rapidly. When 2 or 3 eggs are scrambled together, it usually takes a minute or less before the cooking process is complete. A larger quantity of eggs will require several more minutes.
It is best to remove the eggs from the heat source when they are still very moist, because the internal heat of the eggs will complete the cooking process. Eggs that become too dry indicate that they have been overcooked.
An omelet is usually made with 2 or 3 eggs and is cooked very quickly in a sautÃ© pan. The bottom of the pan should be about 7 to 8 inches in diameter so that the eggs will be no more than Â¼" in height in the pan. A nonstick pan works very well, but the professionals use an iron pan with a long handle that can be exclusively used for omelet making. A properly seasoned iron pan can be cleaned after each use by simply wiping it with a clean cloth or paper towel. Salt is then rubbed on the pan and wiped clean after each use. The salt treatment helps prevent eggs from sticking to the pan the next time it is used.
To prepare an omelet, crack open 2 or 3 eggs over a bowl, add salt and pepper, and stir the eggs just until the whites and yolks begin to blend. The eggs should not be vigorously beaten.
Place the sautÃ© pan on high heat and thoroughly coat the bottom and sides with butter. After the butter is melted, it will begin to foam. The pan is hot enough to continue when the foaming stops, but the butter has not begun to brown.
When the eggs are poured into the pan, they should begin to coagulate almost immediately.
With a few side to side movements of the pan, distribute the eggs evenly.
After a few more seconds, the eggs should be cooked enough to begin forming the mass into an omelet shape.
Jerking the pan toward you should cause the omelet to roll over upon itself as it hits the side of the pan. Continue doing this for few seconds until the omelet is folded into a pleasing form. The omelet should be tender and moist. A dry omelet indicates that it has been cooked too long. Tilt the omelet from the pan onto a plate and it is ready to serve. The actual cooking time is usually no more than 30 to 45 seconds.
Additional ingredients, such as herbs, can be added to the eggs before they are cooked without changing the way the basic omelet is cooked. Other ingredients, such as cheese or finely chopped meats, can be added just before finishing the cooking process. The extra ingredients will probably require that a spatula be used to fold the omelet in the pan rather than trying to roll it over by jerking the pan. The extra ingredients can also be placed on top of the plain omelet when it is served.
A Frittata is an Italian version of the French omelet. It is open-faced and is not folded over like a French omelet and the preparation is also a bit different. A French omelet is cooked very quickly on high heat and any other ingredients such as cheese or vegetables are placed on the omelet just before it is folded over. A frittata is cooked more slowly and any additional ingredients are stirred into the eggs and cooked at the same time. A frittata is substantial enough to be served as a lunch or dinner entree.
Shirred eggs are prepared as a broiled or baked egg dish. Eggs are placed in small buttered dishes referred to as ramekins and broiled until the white is set, but the yolk remains liquid. The eggs may also be baked, but the cooking time is longer and the eggs may become tough and rubbery if cooked too long. Variations of the basic shirred egg may include the addition of herbs, cheese, and/or cream.
A roasted egg is prepared using two different cooking processes. It is first hard-cooked in simmering water and then it is placed in the oven and roasted in the shell. It is removed from the oven when the shell becomes brown. This method is used to prepare eggs traditionally served during the Jewish Passover.
Note: An important point to consider in order to achieve good results (regardless of the cooking method) is that eggs should not be overcooked. Eggs cooked too long or at too high a temperature may become tough and rubbery and will not be very appealing. Unless eggs are rapidly cooled, they continue cooking after removal from the heat source.
Egg Shopping Guide
Composition | Color | Size | Grades | Freshness
An egg is composed of several structures that all serve an important function its construction. Besides the shell, yolk, and white, there is the air cell, chalaza, vitelline membrane, and shell membranes. It is helpful to understand the function and importance of each structure to obtain knowledge that can be useful when shopping for eggs as well as preparing them.
The shell is the outer covering of the egg which protects the contents from damage and contamination. The shell is composed mainly of calcium carbonate and may contain as much as 12% of the total weight of the egg.
The surface of the shell is covered with thousands of microscopic holes which makes it quite porous. A natural coating referred to as the the “bloom” helps seal the holes, preventing bacteria from entering. As the egg ages, the bloom is worn away, which allows moisture to slowly escape and air to enter, forming the “air cell”. Bacteria may also enter, and contamination may result. When eggs are packaged for sale to consumers, they are carefully washed to remove germs that may be on the surface. This removes the bloom, so a thin coating of oil is applied to take the place of the bloom. This works in the same way as the bloom, keeping the contents fresh for longer periods.
The thickness and strength of the shell are determined mainly by the age of the hen and the hen’s diet. Calcium, Vitamin D, and phosphorous are important nutrients in the hen’s diet in order to promote proper shell formation. Hens produce larger eggs as they age, but the thickness of the shell decreases because the same quantity of shell material is produced which must cover a larger volume of contents.
After the egg is laid and then cools, the contents contract allowing air to be trapped between the two membranes beneath the shell. The trapped air produces an"air cell" which forms at the large, rounded end of the egg. The size of the air cell is one of the criteria used when grading eggs. The air cell is visible as the egg passes in front of a bright light (candling).The smaller the air cell, the higher the grade of the egg. The size of the air cell increases as the egg ages. An egg may actually float in water if it is very old, indicating that the contents has lost moisture and the air cell is very large.
The egg white, also known as the albumen, surrounds the yolk with four different layers. The layers alternate from thin nearest the shell, to thick, to thin again, and finally to thick again nearest the yolk. The individual layers are referred to as:
- Thin outer white: the layer nearest the shell.
- Thick outer white: the layer after the thin outer layer, moving toward the inside.
- Thin inner white: the layer after the thick outer layer, moving toward the inside.
- Thick inner white: the layer next to the yolk membrane.
The egg white accounts for about two-thirds of the liquid mass of the egg and contains over half of the protein content. It has none of the egg’s cholesterol, which averages 213 milligrams and is all contained within the yolk. The egg white is not actually white in color, but is opalescent. It is not until the egg is beaten or cooked that the albumen turns an opaque white.
The chalaza is a thick strand of the egg white that serves as an anchor. It helps to hold the yolk in the center of the thick, inner white layer. The chalaza does not have to be removed before preparing the egg and it can be beaten or cooked with the rest of the egg without creating any problems. There may be some finely textured dessert recipes, such as custards, that may benefit from its removal, but it isn’t a necessity.
The yellow center portion of the egg is known as the yolk. The liquid content of the yolk is enclosed by the vitelline membrane which protects the yolk from breakage. As the egg ages, the vitelline membrane loses some of its strength, so the yolk is more apt to break.
Compared with the egg white, the yolk has a greater proportion of the egg’s nutrients. Some of the egg’s nutrients, such as zinc, vitamin A, vitamin D, and vitamin E, are fully contained within the yolk. About 1/3 of the liquid mass of the egg is contained within the yolk, but it contains 100% of the egg’s fat content and cholesterol and nearly half of the protein.
The egg shell and/or the yolk may differ in color from one egg to the next. An egg shell color other than the usual white and a yolk that is not a perfect golden yellow do not indicate that there is a problem with the egg or that there will be any difference in the flavor, nutrition, or other characteristics.
The shell color of a chicken egg is determined by the breed of the chicken. An egg with a brown shell is laid by a breed of hen with reddish colored feathers such as the Rhode Island Red. White eggs are laid by hens with white feathers. Even though there is no difference between white and brown eggs other than the shell color, brown eggs are slightly more expensive because the birds are larger and require additional food. The extra cost of the additional feed results in extra cost for the consumer.
The color of the egg yolk is usually determined by the hen’s diet. Feed produced with yellow or orange ingredients results in the usual golden color of the yolk. Lighter colored ingredients result in paler, lighter yolks. Natural ingredients with yellow or orange pigments may be mixed with feed to brighten the yolk color, but the addition of artificial pigments is not allowed.
A blood spot may be found on the egg yolk, but this is a rare occurrence. Most eggs with blood spots are removed during the candling operation, but a few may slip through and reach the consumer. The blood spot does not affect the quality or flavor of the egg and it actually indicates that the egg is very fresh because the blood spot tends to get diluted as the egg ages.
Eggs are available in several sizes and are referred to as peewee, small, medium, large, extra large, and jumbo. The most common sizes that are available to consumers are medium, large, and extra large.
The size of the egg is determined by several factors including:
* The age of the hen * The breed of the hen * The weight of the hen * Nutrition * Environmental conditions
The net weight in ounces per dozen is the standard that is used to classify egg sizes.
* 1 dozen medium eggs = 21 ounces * 1 dozen large eggs = 24 ounces * 1 dozen extra large eggs = 27 ounces
Many recipes requiring eggs specify the use of large eggs, so if the eggs you have available are smaller or larger, it is beneficial to know the size equivalents. Use the following guidelines to achieve a quantity that should work well for most recipes.
* 5 medium eggs = 4 large eggs = 4 extra large eggs * 6 medium eggs = 5 large eggs = 4 extra large eggs * 7 medium eggs = 6 large eggs = 5 extra large eggs
For a more precise measure:
* 1 medium egg = 3 tablespoons * 1 large egg = 3Â¼ tablespoons Therefore: * 13 medium eggs yields exactly the same quantity (39 tablespoons) as 12 large eggs.
The grade of an egg refers to the quality of the egg and has nothing to do with the size. The interior of the egg is inspected as well as the exterior. In order to inspect the contents of the egg, a process called “candling” is used. Candling is the process of passing eggs in front of bright lights to reveal the contents inside the shell. Before the development of electric lighting, eggs were passed in front of candle flames, which is how the name “candling” came about. Among the characteristics that determine the quality of eggs are:
* Shell: Is the shell a good shape or is it abnormally formed? Are there cracks, stains, rough spots, or ridges? * Air cell: Is the air cell barely noticeable or is it quite large? Higher grade eggs have a small air cell, indicating that the egg is very fresh. The size of the air cell increases as the egg ages. * Appearance after breaking: Does the egg cover a small area when it is opened or does it spread out into a wider area? The contents of a higher quality egg will cover a smaller area. * Albumen: The proportion of thick white compared to the thin white should be greater in a high grade egg and the chalaza should be very noticeable. * Yolk: A high grade egg should have a yolk that is plump and round. The yolk in a lower grade egg is flattened and limp. * Blood spots: If egg yolks have blood spots, they are typically removed, although the blood spot does not affect the quality or flavor of the egg.
The USDA classifies eggs with the following grades:
Grade AA This is the highest quality possible. Because of their quality, grade AA eggs can be used for any purpose, but are especially useful for cooking methods in which the egg is cooked in the shell.
Grade A The quality is slightly less than that of a grade AA, but most consumers wouldn’t notice the difference. The air cell is slightly larger, the proportion of thick to thin albumen is not as great, and the contents may spread out a bit more once the egg is cracked open. A and AA are the grades that consumers will find in food stores.
Grade B The decrease in quality is much more noticeable. The shell may be discolored, blemished, and oddly shaped. The air cell may be very large and the contents more runny, but the nutritional value is the same as higher grades and the flavor is similar. Most grade B eggs are used by commercial operations that produce egg products and some are used by commercial bakers.
The picture below shows the USDA seal
for “Grade A” eggs in the upper right corner of the carton.
“Grade AA” eggs
The freshness of an egg is not only determined by the date when the egg was laid, but also by the way the egg has been stored. Proper handling and storage is perhaps the most important factor in determining freshness. If a freshly laid egg is left at room temperature for a full day, it will not be as fresh as a week old egg that has been refrigerated between 33Â° and 40Â°F from the time it was laid.
USDA (United States Department of Agriculture) inspected eggs have a date stamped on the carton indicating the last day that the eggs can be legally sold. This “sell by date” is no more than 30 days beyond the date the eggs were packed. Eggs are usually packed within a week of being laid, but they may be packed as long as 30 days after being laid, which is within USDA regulations. The pack date is a 3 digit code that is stamped on the carton near the sell by date. Each day of the year is given a number from 1 to 365, with January 1st indicated by the number 1 and December 31st indicated by the number 365. The number 105 on the carton shown indicates that the eggs were packed on April 15, the 105th day of the year. (The number to the left of 105 is a code number used by the packing company). Eggs can be sold up to a month after the packing date and if they are properly refrigerated, they are generally safe to eat as much as a month after the sell by date. A general rule to follow is that any egg that looks or smells odd should not be used.
Egg Handling, Safety & Storage
Cleanliness | Contamination | Doneness | Pasteurization | Proper Storage
It is important to follow the basic rules of cleanliness and proper hygiene when preparing eggs and egg products. Wash your hands before and after egg preparation. If multiple foods are being prepared at one time, your hands should be washed thoroughly after preparing each different food item to avoid spreading possible bacteria from one food to another (cross contamination) and to yourself.
Cutting boards used in the kitchen are best when they are constructed of non-porous materials such as tempered glass or heavy plastic. Tempered glass cutting boards are safer to use because there is less of a problem with cracks and pores harboring bacteria as there is with wood or soft plastic surfaces. Cutting boards should be washed thoroughly after each use with hot, soapy water. A mixture of bleach and water or an antibacterial spray can also be used to kill germs. All other work surfaces, such as countertops, and all utensils used in food preparation should also be thoroughly cleaned.
Beware of kitchen washcloths and towels that have been used on multiple surfaces because they can spread germs. Use paper towels or other disposable cloths whenever possible. Eggs that are cracked, leaking, and/or soiled should not be used.
The risk of eggs being contaminated with harmful bacteria and causing illness is very low. The odds of becoming ill from consuming eggs is no greater than with any other perishable type of food and the risk is often less than many foods. It is estimated that only 0.005% (1 in 20,000) of eggs may be contaminated with the salmonella bacteria, but even with a risk this low, it is wise to cook eggs to the proper doneness to ensure safety. Proper cooking kills the salmonella bacteria in any eggs that may have it.
The eggshell is a good natural barrier for preventing bacteria from entering the egg, but since it is porous, it does not guarantee that an egg will remain germ free. Other barriers, such as the shell membrane, the four layers of the white, and the yolk membrane (vitelline) help to prevent bacteria from entering the yolk, which is a perfect environment for bacteria to thrive.
The eggshell may contain other types of bacteria and dirt, so in the United States, eggs are thoroughly washed before they are sold to the consumer. After sanitizing, eggs are usually given a light spray of mineral oil to coat the shell, replacing the natural protective coating that was lost during the washing.
In eggs that are contaminated with salmonella, the bacteria are more likely to be found in the white, but are unable to thrive because of the lack of nutrients. The white is an alkaline substance which also discourages the growth of bacteria. The egg white acts as a natural protection for the yolk, preventing bacteria from entering the yolk and thriving in the nutrient rich environment. The white thins out as the egg ages, which makes it easier for bacteria to reach the yolk.
Refrigeration slows bacterial growth, so it is important to properly store eggs. Never use eggs that are cracked or leaking or stuck to the bottom of the carton. Even if there isn’t a visible crack, an egg that is stuck to the carton, even slightly, may indicate that it has leaked and should not be used.
Cross contamination is also important to guard against. Various types of foods should be kept separate from each other during storage and preparation. Never store ready to eat foods next to raw eggs, raw meats, or raw fish. Germs from perishable food items may contaminate the ready to eat foods. If cutting boards are used in your kitchen, it is a good idea to use one for meats and a different one for fruits and vegetables. Never use the same knives and utensils for preparing multiple food items unless they are washed before using them on a different item. The knife that was used to cut raw beef should not be used to chop a hard-cooked egg unless the knife has been thoroughly washed first. It is also important to wash your hands often during food preparation to avoid transferring harmful bacteria from one food item to the next. If you were handling raw meat, for example, you would want to wash your hands thoroughly before chopping vegetables to reduce the risk of transferring bacteria from the meat to the vegetables.
Additional Points to Consider Concerning Contamination
* It is best not to separate egg whites and yolks by splitting open the eggshell and passing the contents between the two shell halves. The egg may become contaminated if bacteria are present on the shell. Bacteria may be present on the shell even after it is cleaned and the shell may also become contaminated from other food sources that it may come in contact with. * Do not use the two halves of the shell for removing bits of the shell from an egg mixture and never use the shell halves to measure other foods for a recipe. * Salmonella may be found not only in eggs, but in other foods such as chicken, cheese, orange juice, tomatoes, and alfalfa sprouts. It can be spread quite easily from one food to another, which is why it is important to guard against cross contamination during food preparation. * Cross contamination can occur when bacteria are transferred from one food to another, from contaminated kitchen equipment to food, or from people to food. * The number of incidents of people becoming infected from salmonella in eggs has steadily declined during the past few years. This is due mainly to quality control measures on the farm, in processing facilities, and during shipping to food stores and also because of increased awareness of proper food handling procedures by food service personnel and consumers.
The best way to guard against the spread of bacteria and foodborne illness is to cook eggs thoroughly. Cooking eggs thoroughly does not mean that the eggs should be overcooked, which can make them tough and rubbery. It simply means the eggs should be cooked to a temperature that kills any bacteria that may be present. Most harmful bacteria cannot survive in a temperature of 160Â°F or greater. In fact, salmonella is killed instantly when subjected to a temperature of 160Â°. An egg (white and yolk) requires a temperature of up to 158Â°F before it sets properly. The white alone requires a somewhat lower temperature before it coagulates, usually in the 140Â° to 150Â° range. These temperatures are only slightly less than what is required to destroy all of the harmful bacteria that may be present, so heating eggs to 160Â° F should not cause eggs to be overcooked, unless they are held at that temperature (or higher) for an extended period.
Cooking eggs slowly with heat that is not too high should destroy harmful bacteria as well as allow for proper doneness. There are exceptions to this, such as when cooking a plain omelet. The eggs are cooked very quickly, but the heat is also much higher, which takes care of any possible bacterial contamination. Baked egg dishes can be checked using a kitchen thermometer placed in the center of the dish. The thermometer should register 160Â°F to ensure proper doneness.
Eggs cooked in the microwave may not cook evenly, so it is important to rotate the dish several times during the cooking process. Covering the dish during microwave cooking is recommended because steam is trapped inside the dish, which helps to cook the eggs more quickly and evenly and keeps them from drying out.
Pasteurized Egg Products
In the United States, all egg products that are distributed to the consumer must be pasteurized. The products include whole eggs, whites, and yolks that may or may not be blended with other ingredients to add volume or flavor. The pasteurization process destroys any harmful bacteria that may be present in the eggs at the time of processing, but it does not guard against future contamination. It is important to properly handle and store pasteurized egg products to help prevent future contamination. Egg products are typically produced in liquid, dried, or frozen varieties. Look for the USDA mark of inspection on pasteurized products.
Pasteurized Shell Eggs
Pasteurized shell eggs are heated for a period of time to destroy any bacteria that might be present, but the process does not cook the eggs. The eggs are safer to use for a number of recipes that traditionally call for the use of raw or partially cooked eggs, however the USDA still recommends using the eggs in dishes that are fully cooked, especially when serving the dish to higher risk persons such as people with weakened immune systems, young children, or elderly people.
There is no difference in the outcome of cooked or baked egg dishes when using pasteurized shell eggs as opposed to untreated eggs, however there is a noticeable difference between pasteurized and non-pasteurized shell eggs in the time required for beating the egg whites into peaks. Pasteurized egg whites may require 3 to 5 times the beating time required for untreated eggs. Instead of using whole pasteurized shell eggs for recipes requiring beaten egg whites, you can use pasteurized egg whites that are in a liquid state or have been dried into a powder. Some pasteurized egg white products are available containing no other ingredients while some contain additives that help in building volume when beating egg whites and to stabilize the foam.
Eggs should never be stored at room temperature, but there are recipes that require eggs to be at or near room temperature before incorporating them into the other ingredients in the recipe. Egg whites that will be beaten should be at room temperature because this helps the whites to reach their maximum volume when beaten. Approximately 30 minutes is required for eggs to reach room temperature after removing them from the refrigerator. Eggs should not be away from refrigeration for more than 2 hours, so the time required to allow the eggs to warm to room temperature, as well as the total preparation time of the recipe, should not exceed the 2 hour maximum. This should be considered when planning the steps required for the preparation of a recipe using eggs that must be at room temperature.
Eggs should be stored in the refrigerator in the carton they were packed in. Many refrigerators provide storage for eggs in special units in the door, but this is not the ideal place for storing eggs because the temperature fluctuates so much in the door when it is opened and closed. Eggs should be stored in the coldest part of the refrigerator where the temperature remains constant. Eggs keep best when they are stored at temperatures of no higher than 40Â°F. The ideal temperature range is 33Â°F to 38Â°F. When the temperature is above 40Â°F, harmful bacteria may grow rapidly. Although salmonella are not destroyed in temperatures below 40Â°F, any of the bacteria that may be present will not multiply when the temperature is below 40Â°F.
Eggs should be stored with the rounded end pointed up in order to keep the air cell on top and to help keep the yolk centered in the egg. Never store eggs next to strong smelling foods because eggshells are porous and will allow strong odors to be absorbed into the egg over time. This is another reason why it is a good idea to store eggs in the original protective carton.
For long term storage, eggs and egg products may be frozen. If stored properly, eggs will emerge from the freezer no better or worse, in terms of quality, than when they first entered the freezer. The temperature of the freezer compartment must be at 0Â°F or less and the eggs should be stored in an area of the freezer where there is the least amount of temperature change. Eggs and egg products should not be stored in the door compartment of the freezer, especially if the door is opened frequently.
Whole eggs can be beaten slightly and placed in a container with a tight seal and stored in the freezer for as long as a year. Egg whites may be stored in the freezer for up to a year in a tightly sealed container. Egg yolks may also be stored in the freezer, but sugar or salt must be added to keep the yolks from becoming too thick and gelatinous over time. Add a pinch of salt per yolk if the yolks will be used for savory dishes or about a Â¼ teaspoon of sugar per yolk if the yolks will be used for sweet dishes.
Like other perishable foods that have been frozen, eggs should be defrosted in the refrigerator and should never be allowed to thaw at room temperature. Thawing foods on the countertop encourages the the growth of harmful bacteria, especially on the outside edges of the food.
Egg Tips & Substitutions
* Scrambled Eggs: Scrambled eggs may turn slightly green if cooked at too high a temperature or allowed to sit in the pan for long periods. To help prevent this, always serve scrambled eggs when they are still moist and do not hold them in the pan for long periods. If the eggs must be held for awhile before serving, place the pan in another pan containing warm water to keep the eggs heated rather than keeping them directly on a burner. Covering the pan will also hold in moisture. * Hard-Cooked Eggs: If your hard-cooked eggs happen to become mixed up with uncooked eggs, it is easy to figure out which is which. If you spin an egg on its side on a flat surface and it does not wobble, it indicates that the egg is hard-cooked. * Poached Eggs: Adding a bit of vinegar to the poaching water will help set the eggs more quickly, creating a pleasing shape, and helping to prevent streamers of egg white from moving outward from the egg.
* It may not be possible to substitute egg whites for whole eggs for some baked recipes without encountering poor results, but it is possible to use only egg whites for egg dishes such as scrambled eggs or omelets in order to eliminate the cholesterol. * When making scrambled eggs or an omelet, use 2 egg whites and 2 whole eggs to create the same volume as 3 whole eggs. This allows you to enjoy egg yolks while cutting down the cholesterol level. * Recipes that traditionally call for raw or partially cooked eggs may benefit from the use of egg substitutes such as egg white substitutes, meringue powder, or pasteurized whole eggs. The risk of bacterial contamination is greatly reduced with the use of these products.
Pasteurized Shell Eggs
Pasteurized shell eggs are heated for a period of time to destroy any bacteria that might be present, but the process does not cook the eggs. They are more expensive than unpasteurized eggs, but are a good alternative for use in raw or partially cooked egg recipes. The eggs can be used in egg dishes and for baked items just like eggs that are not pasteurized. The shells are stamped to signify that the eggs have been pasteurized.
Liquid Whole Eggs
Eggs without the shells are available as a pasteurized white and yolk blend and are usually packaged in 1 cup and 1 pint containers. The pasteurization process destroys any harmful bacteria that may be present in the eggs at the time of processing. Unopened containers will last as long as 3 months under proper refrigeration.
Liquid Egg Whites
When egg whites are needed for an uncooked dish, you can purchase pasteurized egg whites that are already separated from the yolks. The egg whites are usually packaged in pourable containers and are convenient for cooks who use more egg whites than yolks. Because of the pasteurization process, the beating time necessary for meringues may be 3 to 5 times longer than the beating time required for unpasteurized egg whites.
Liquid Egg Yolks
Pasteurized egg yolks that are already separated from the whites, can be purchased. The egg yolks are usually packaged in pourable containers and are convenient for cooks who use more egg yolks than whites.
Liquid Egg Substitutes
Egg substitutes are packaged and sold as refrigerated or frozen food items. The main purpose of egg substitutes is to cut down or eliminate the high cholesterol content of eggs. All of the cholesterol is contained within the yolk, so most substitutes are produced using egg whites only, with other ingredients added as a substitution for the yolks. Some of these additional ingredients may include tofu, skim milk, starch, and artificial flavorings. Egg substitutes are often used for scrambling or for preparing omelets.
Powdered Whole Eggs
Powdered whole eggs are another alternative to fresh eggs and are convenient to use and store. They can be used for most types of egg dishes or recipes requiring eggs. The powder is simply blended with water to produce liquid eggs, which are then used just like fresh eggs. Powdered egg products are pasteurized and do not require refrigeration, making them safe to use and easy to store.
Powdered Egg Whites
Pasteurized powdered egg whites are available containing no other ingredients while some contain additives to help build volume and stabilize the foam when beating egg whites. The freeze-dried egg whites are simply blended with water to produce liquid egg whites, which makes them convenient to use. They also have a very long shelf life (over one year) and do not require refrigeration.
Powdered Egg Yolks
Powdered egg yolks are blended with water to produce liquid egg yolks, which makes them convenient to use. The freeze-dried yolks have a very long shelf life (over one year) and do not require refrigeration.
Meringue powder is basically dried egg whites with the addition of sugar and gum. Meringue is created when the powder is added to water and is then whipped. Like all other uncooked egg products, meringue powder is pasteurized so it is very useful when preparing dishes requiring uncooked meringues. It also has a long shelf life (over one year).
Powdered Egg Substitutes
Powdered egg substitutes are produced using egg whites only, with other ingredients added as a substitution for the yolks. This results in a product that is low in calories and has no cholesterol or fat. Some of the ingredients used instead of the yolks include starch, yeast extract, gum, and artificial flavorings and color. Egg substitutes are often used for scrambling or for preparing omelets. They are easily prepared by just adding water.
Frozen Egg Products, Uncooked
Several types of uncooked egg products are frozen for long term storage. Various blends of whites and yolks and eggs that have been separated, can be purchased. Like refrigerated liquid eggs, frozen uncooked egg products are pasteurized.
Frozen Egg Products, Cooked
Other frozen egg products include convenience foods that are fully cooked such as scrambled egg products, omelets, fried eggs, and complete breakfasts featuring eggs that are microwavable.
Eggs that are pickled are usually marinated in a liquid solution and packaged in jars. The marinade may consist of a mixture of vinegar, herbs, and spices, or it may be a solution of cider or pickled beet juice. Pickled eggs are served in salads or as an hors d’oeuvre, appetizer, or garnish and require refrigeration after the jar is opened.