Copyright © 2000 Sarah Phillips Sarah Phillips, Inc. All rights reserved.
Eggs are the backbone of many baked goods and contribute to its structure. Eggs also provide steam for leavening or moisture for starch. Egg yolks add moisturizing fat and helps emulsify the batter, giving the baked good a smooth and creamy texture. The egg whites act as strengtheners. There are substitutes for fresh eggs, but they do alter the recipe.
Exquisitely simple, yet enormously complex, the egg is one of nature's marvels. The eggs used in baking mainly come from hens.
Eggs' cooking properties are so varied, in fact, that eggs have been called "the cement that holds the castle of cuisine together." They can be substituted, but I always add "with caution."
Whole Eggs: Contain a yolk and a white. These are encased in a shell. They can be beaten with sugar until they "ribbon." Large eggs(50 grams each) are used in baking recipes and they can be separated into whites and yolks.
Egg yolk's structure:
Egg white's structure:
Egg Yolks: It is the yolk or yellow portion which is responsible for the egg's emulsifying properties from the fat and lecithin contained in them (whites do not contain fat). Both contribute to the fine texture of baked goods and which bring the water and fat phases together in a recipe for a creamier, smoother texture. This is important when baking and making creamy sauces. Egg yolks can be beaten with sugar until they "ribbon."
The yolk also contains a little less than half of the protein. With the exception of riboflavin and niacin, the yolk contains a higher proportion of the egg's vitamins than the white. The yolk of a large egg contains about 59 calories. The downside is it contains 213 mg of cholesterol, a significant percentage of the American Heart Association's suggested limit of 300 mg per day.
Egg Whites: Also known as albumen, it accounts for most of an egg's liquid weight, about 67%. Two dried egg white products pasteurized dried egg white powder and meringue powder, can be used in recipes. They are both available at kitchenware and cake decorating shops, bakery suppliers, some supermarkets and by mail-order.
The protein found in the egg white, or albumen, is albumin. Albumen is more opalescent than truly white. The cloudy appearance comes from carbon dioxide. As the egg ages, carbon dioxide escapes, the albumen of older eggs becomes more transparent than that of fresher eggs.
When egg yolks, which contain a fatty substance that destroys the albumen's ability to foam, are removed, egg whites, when beaten vigorously, can foam and increase in volume by up to 6 to 8 times. Egg foams are essential for making meringues, soufflés, puffy omelets, and angel food and sponge cakes.
The ability of the egg white to foam is possible through a close teamwork between two egg white proteins, albumin and ovalbumin. It's the albumin proteins, when beaten, form a stable mass of tiny air bubbles, while some of the protein molecules bond and form a fragile network that holds the moisture in place (an egg white contains at least 85 percent water). While ovalbumin does not play an important role when the egg whites are simply beaten, it coagulates when heated, forming its own network and making it resistant to collapse as the water evaporates.
Chalazae: is the cord looking thing hanging from the egg. The fresher the egg the stronger or pronounced the chalazae. Chalazae is a Greek word that means hailstone. What's important is that it's essentially a rope of egg white that twists itself into being as the egg travels from the ovary to the nest. Its sole purpose is to keep the yolk centered in the egg. Remove it before using the egg. You may also have to strain stirred custard after making to get rid of them or pieces.
Egg Coagulation: The term Coagulation means the conversion of a semi-liquid to a gel state. Egg is a protein and when egg is exposed to heat then its proteins which are in the liquid form are converted in a gel like form and this is known as Egg Coagulation. The water content of egg is reduced because the formation of the three dimensional protein molecules result in trapping water content. When egg Coagulation is carried out, it start showing the characteristics of solid. Egg Coagulation takes place at about 145 degrees F for a few minutes.
SIZE DOES MATTER! The grades of eggs are defined by the USDA. They are AA, A, B, C. Most of the eggs on the market are Grade AA, or A. The B and C eggs go in for pet foods and other egg products.
1 cup (240 ml) = 4 whole eggs, or 12 egg yolks, or 7 to 8 egg whites
Although any size egg may be used for frying, scrambling, cooking in the shell or poaching, most recipes for baking have been developed on the basis of a 48 (1.6931502 ounces) to 50 grams (1.7636981 ounces) egg (weight), or a large one, unless otherwise specified. I always use 50 gram weight (20 gram yolk and 30 gram white) for Grade A, large eggs in my baking recipes even if it indicates to use just "eggs".
USES OF EGGS: Eggs have many uses in baking and cooking. They can bind ingredients as in meatloaves or croquettes. They can also leaven such baked high rises as soufflés and sponge cakes. Their thickening talent is seen in custards and sauces. Eggs emulsify mayonnaise, salad dressings and Hollandaise sauce and are frequently used as a glaze to coat breads and cookies. They clarify soups and coffee. In boiled candies and frostings, eggs retard crystallization. They also enable coating. In general, eggs add color and flavor. As a finishing touch, they can be hard cooked and used as a garnish.
ARE ROOM TEMPERATURE EGGS REALLY IMPORTANT?
SARAH SAYS: NO! Some recipes call for adding room temperature eggs. But, I have found that you can use eggs right from the refrigerator. It’s ok!
A typical step in a buttercake recipe is to cream with fat and sugar and then add in the eggs, one at a time. This creates an emulsion. Fat and liquid by nature are unmixable, and the goal when mixing a recipe is to form a water-in-fat emulsion. A well emulsified cake batter, for example, should not be curdled or weeping liquid, which happens if cold eggs are introduced to a room temperature butter/sugar mixture. If the emulsion breaks, the batter will loose air cells and result in a baked cake that is grainy or flat in texture, dry and flavorless, look uneven and may even sink.
But, when using today’s electric stand mixer, you can add in COLD EGGS, right from the refrigerator. It’s because the beaters quickly warm the eggs to the proper temperature. The batter will curdle slightly, which is fine; when you add in the flour, the batter will become smooth and perfect, again.
WAYS TO MAKE EGGS SAFE
Plain whole eggs without added ingredients are pasteurized but not cooked by bringing them to 140 degrees F and maintaining that temperature for 3 and 1/2 minutes. According to the FDA Food Code, eggs for immediate consumption can be cooked to 145 degrees F for 15 seconds.
If the eggs are to be used in a recipe with other food items, dilute the eggs with liquid or other ingredients, such as milk, or sugar (at least ¼ cup liquid or sugar per egg as in custard) and cook the egg mixture to 160 degrees F, which will destroy harmful bacteria in a few seconds. Adequate cooking brings eggs and other foods to a temperature high enough to destroy bacteria that might be present.
QUESTION: What should I do about some of my favorite egg recipes that call for raw or lightly cooked eggs?
SARAH SAYS: Although the overall risk of egg contamination is very small, the risk of foodborne illness from eggs is highest in raw and lightly cooked dishes. To eliminate risk and ensure food safety, replace all your recipes calling for raw or lightly cooked eggs with cooked egg recipes or use pasteurized raw eggs or powdered and pastuerized egg products when you prepare them. To cook eggs for these recipes, use the following methods to adapt your recipes:
Cooking Whole Eggs for Use in Recipes – As a nutritious combination of egg whites and yolks, whole eggs should be fully cooked for assured safety in recipes that call for raw or lightly cooked eggs. The following method can be used with any number of eggs and works for a variety of recipes.
In a heavy saucepan, stir together the eggs and either sugar, water or other liquid from the recipe (at least 1/4 cup sugar, liquid or a combination per egg). Cook over low heat, stirring constantly, until the egg mixture coats a metal spoon with a thin film or reaches 160° F. Immediately place the saucepan in ice water and stir until the egg mixture is cool. Proceed with the recipe.
Cooking Egg Yolks for Use in Recipes – Because egg yolks are a fine growth medium for bacteria, cook them for use in mayonnaise, Hollandaise sauce, Caesar salad dressing, chilled soufflés, chiffons, mousses and other recipes calling for raw egg yolks. The following method can be used with any number of yolks.
In a heavy saucepan, stir together the egg yolks and liquid from the recipe (at least 2 tablespoons liquid per yolk). Cook over very low heat, stirring constantly, until the yolk mixture coats a metal spoon with a thin film, bubbles at the edges or reaches 160° F. Immediately place the saucepan in ice water and stir until the yolk mixture is cool. Proceed with the recipe.
Cooking Egg Whites for Use in Recipes – Cooking egg whites before use in all recipes is recommended for full safety. The following method can be used with any number of whites and works for chilled desserts as well as Seven-Minute Frosting, Royal Icing and other frosting recipes calling for raw egg whites.
In a heavy saucepan, the top of a double boiler or a metal bowl placed over water in a saucepan, stir together the egg whites and sugar from the recipe (at least 1/4 cup per white), water (1 teaspoon per white) and cream of tartar (1/8 teaspoon per each 2 whites). Cook over low heat or simmering water, beating constantly with a portable mixer at low speed, until the whites reach 160° F. Pour into a large bowl. Beat on high speed until the whites stand in soft peaks. Proceed with the recipe.
Note that you must use sugar to keep the whites from coagulating too rapidly. Test with a thermometer as there is no visual clue to doneness. If you use an unlined aluminum saucepan, eliminate the cream of tartar or the two will react and create an unattractive gray meringue.
Making an Italian Meringue Buttercream by adding hot sugar syrup to egg whites while beating them does not bring the egg whites to much above 135 degrees F and does not fully pasteurize them. If, however, you bring the sugar syrup all the way to the hardball stage (250 to 266 degrees F), the whites will reach a high enough temperature, used for Divinity and similar recipes.
Pasteurized dehydrated eggs and are already safe; that is, they have been heated sufficiently to kill bacteria and then made into a powdered form. Use them to prepare meringue, eggnog, homemade mayonnaise, or other dishes that require raw eggs.
The egg industry has developed methods for pasteurizing eggs in the shell to destroy salmonella bacteria. Egg products made of plain whole eggs are pasteurized (heated to destroy bacteria), but not cooked, by bringing them to 140° F and keeping them at that temperature for 3 1/2 minutes. NOTE: Separating pasteurized eggs for a recipe is a little trickier and beating the egg whites takes several minutes longer than traditional ones.
An important cooking technique used when making custards is tempering, which is the slow addition of a hot liquid to a cold one. Tempering gradually brings the temperature of the two mixtures together and is used when a scalding hot liquid, such as cream or milk, is added to eggs. To temper, add a large spoonful of the hot cream to the egg-sugar mixture, whisking all the while. Add another spoonful, and then another, and continue until all the cream is mixed in.
HOW TO BUY EGGS:
1. Never buy eggs that haven't been refrigerated because they are potentially hazardous to consume. (There are also egg substitutes and dried egg products).
2. When buying fresh eggs, reach back in the refrigerator case to select the coldest dozen you can. Check on how the eggs look and the carton date. Choose another container if there are any problems.
3. Then, check the dates on the outside of the carton to indicate whether they are fresh or not: CARTON DATE - Egg cartons from USDA-inspected plants must display a Julian date--the date the eggs were packed. Although not required, they may also carry an expiration date beyond which the eggs should not be sold: Julian date is the date the eggs were packed. Starting with January 1 as number 1 and ending with December 31 as 365, these numbers represent the consecutive days of the year. Expiration Date is the date after which the eggs cannot be sold. The expiration date cannot exceed 30 days after the eggs were packed
4. Then open the egg container to make sure none are cracked, broken or dirty. The shells should be clean but slightly dull. Shiny shells are a sign of old eggs.
TEST FOR FRESHNESS: The air cell, or the empty space between the white and shell at the large end of the egg, gets larger as the egg ages. When an egg is first laid, it is warm. As it cools, the contents contract and the inner shell membrane separates from the outer shell membrane to form the air cell. You can see the air cell in the flattened end of a peeled, hard-cooked egg. If you immerse an egg in (cool) water, you can judge how fresh it is by how high it floats. Really fresh eggs won't float at all; the higher it floats, the less likely it is to be fresh. Another way is to shake the egg. Fresh eggs make no sound. Old eggs slosh in the shell.
Blood Spots: Also called meat spots. Occasionally found on an egg yolk. Contrary to popular opinion, these tiny spots do not indicate a fertilized egg. Rather, they are caused by the rupture of a blood vessel on the yolk surface during formation of the egg or by a similar accident in the wall of the oviduct. Less than 1% of all eggs produced have blood spots.
As an egg ages, the white becomes thinner and the yolk becomes flatter. These changes do not have any great effect on the nutritional quality of the egg or its functional cooking properties in recipes.
Appearance may be affected, though. When poached or fried, the fresher the egg, the more it will hold its shape rather than spread out in the pan. On the other hand, if you hard cook eggs that are at least a week old, you'll find them easier to peel after cooking and cooling than fresher eggs.
EGG SUBSTITUTES OR REPLACERS: For those who are allergic to eggs or wish to avoid cholesterol, alternatives are available. Refer to the egg substitutes page.
DO NOT USE RAW EGGS IN UNCOOKED FOODS When using in a recipe that calls for the egg, whites and/or to be raw, either cook them so they're safe or use a pasteurized egg substitute or a dried egg product
DRIED EGG AND EGG WHITE PRODUCTS: Pasteurized egg products are Salmonella free, but they must be handled carefully to avoid contamination.
Pasteurized Egg Powder: Dried egg products are available in the supermarket. Just reconstitute and use. It is spray dried egg albumen, which can be used in most recipes requiring fresh egg whites.
Use in uncooked foods such as marzipan and buttercream icing, or foods which are lightly cooked (pie meringues), without the worries associated with salmonella because it is heat treated to meet USDA egg safety standards. It produces an exceptionally high volume, stable egg white foam for use in angel food cakes, chiffon pies, meringues, and divinity.
Eggology are pasteurized egg whites, sold in liquid form. They have been tested for salmonella and are packaged only 3 days after harvest. Most whole eggs in the supermarket are 6 weeks old when you buy them. The fresher the egg whites the lighter and fresher the texture and taste, they produce more volume and are more stable. Look for them soon in your supermarket. You can find out more about them by calling 1-818-610-2223.
Meringue powder: ONE LARGE EGG WHITE = 2 teaspoons of meringue powder plus 2 tablespoons warm water. Meringue powder is another pasteurized egg white product. This is dried egg whites with sugar, cream of tartar and cornstarch. The powder like dried egg whites, is pasteurized and completely safe from harmful bacteria. It is used for royal icing, meringue and boiled icing. Meringue powder can be used to make safe meringue for pies and other desserts. Meringue cookies are easy to make, as well. Find it in cake decorating stores or online.
General Storage: Unopened dried whites should be stored in a cool and dry place. Once opened, they should be refrigerated.
To reconstitute egg white or meringue powder, just follow the manufacturer's instructions for powder and water measurements. However, I have found that when dissolving the powder, it can be stubborn. So, what I do is:
1. Use tepid (not hot) water, which helps to dissolve it;
2. Sprinkle the powder on the water, stir it to moisten all of it. Let it sit for a good 5 minutes, stirring half way through. Some of the powder will clump and stick to your spoon so I like to use a chopstick to minimize it. Rub the clumps in between you thumb and forefinger and try to dissolve. If they are hard, discard;
3. Once dissolved, be sure to stir the mixture well. If you whip it slightly with a whisk it should foam -- that means it's done; and,
4. If you find undissolved hard clumps of powder, unfortunately you have to start over; they will not dissolve on their own even when the recipe bakes.
How to make egg glaze or wash: Beat 1 egg with 1 - 2 teaspoons water or milk. The only purpose for the liquids in an egg wash is to dilute the egg proteins sufficiently so it spreads easily across the surface. If it doesn't, add a little more water or milk. In the heat of cooking, the proteins of the egg will contribute a slightly shiny surface, and will brown easily
STORAGE: All eggs will begin to deteriorate upon storage. The question and problem is how to minimize
Always store eggs in their carton and leave the shells unwashed; they contain a natural protective coating. Each eggshell contains 6,000–8,000 microscopic pores, and eggs pick up odors if stored uncovered. Place them round side up to keep the egg yolk centered in the white and away from the air pocket.
Left-overs: In preparing recipes, you may have some left-over whole eggs, whites and/or yolks.
When storing, always label covered containers in which you store the insides of these eggshells with the number they contain and the date stored. Use them within 2 to 3 days in a fully cooked dish or freeze them for later use.
Store in Refrigerator: Store whole eggs from their shells for 2 - 3 days, covered tightly.
If the eggs are separated, you can refrigerate raw whites for up to 4 days and unbroken raw yolks, covered with water, for up to 2 days in a tightly sealed container. If you can’t use the yolks quickly enough, hard cook them just as you would cook whole eggs in the shell, drain them well and refrigerate them in a tightly sealed container for up to 4 or 5 days. For longer storage, freeze raw whites, sugared or salted yolks and cooked yolks for up to 1 year.
Store in Freezer: It's best to freeze the yolks separately from the whites because they store better. But, if you store a whole egg, whisk it with a pinch of salt or a drop of corn syrup per egg to stabilize the egg proteins.
If separating eggs, crack, separate and store in tightly closed, marked containers. Egg whites: Keep 1 - 3 months. To freeze, place egg whites in a Pyrex custard cup, tightly covered. Some freeze one egg white per ice cube cavity in an ice cube tray, and then transfer them to a plastic, airtight bag. One large egg can be substituted for 2 large egg whites. The whites whip more easily and to a greater volume than fresh egg whites, because their surface tension is reduced through freezing and thawing, giving them greater foaming power. Egg yolks: If you are separating all the eggs, you can save the yolks to use later in another recipe. If freezing alone, becomes gummy and not useable when thawed. So, add in: per 1/4 cup egg yolks, about 3 - 4 (1 egg yolk = 1 tablespoon plus 1/2 teaspoon), mix in 1/8 teaspoon salt, if eventually making a savory recipe or 1 to 1-1/2 teaspoon of sugar or corn syrup, if eventually making a sweet one. The salt or sugar protects the egg proteins.
TO STORE EGG YOLKS: Lightly beat 1/4-cup yolks with 1/8 teaspoon salt (use in savory recipes) or 1 to 1-1/2 teaspoons sugar (use in sweet recipes). Line another bowl with plastic wrap and pour the yolks into the lined bowl. (If freezing one yolk, use a few grains of salt or a pinch of sugar).
Freeze overnight until solid, then wrap the block securely and be sure to mark the date and number of yolks in the package. Double wrap the frozen yolks with plastic or seal with your home vacuum sealer and store in the freezer for up to 3 months. Some freeze one egg yolk per ice cube cavity in an ice cube tray, and then transfer them to a plastic, airtight bag.
To use, thaw in refrigerator and then mix well. They will not look the same as fresh egg yolks do, but they work just as well.