A hen requires 24 to 26 hours to produce an egg. Thirty minutes later, she starts all over again.
The eggshell may have as many as 17,000 tiny pores over its surface. Through them, the egg can absorb flavors and odors. Storing them in their carton helps keep them fresh.
Eggs age more in one day at room temperature than in one week in the refrigerator.
About 240 million laying hens produce approximately 5.5 billion dozen eggs per year in the United States.
White shelled eggs are produced by hens with white feathers and white ear lobes. Hens with red feathers and red ear lobes produce brown-shelled eggs.
To tell if an egg is raw or hard-boiled, spin it! If the egg spins easily, it is hard-boiled but if it wobbles, it is raw.
If an egg is accidentally dropped on the floor, sprinkle it heavily with salt for easy clean up.
During the spring (vernal) equinox (around March 21st), it is said that an egg will stand on its small end. Although some people have reported success, it is not known whether such results were due to the equinox or to the peculiarities of the particular egg.
Egg yolks are one of the few foods that naturally contain vitamin D.
Yolk color depends on the diet of the hen. Natural yellow-orange substances such as marigold petals may be added to light-colored feeds to enhance color. Artificial color additives are not permitted.
Occasionally, a hen will produce double-yolked eggs throughout her egg-laying career. It is rare, but not unusual, for a young hen to produce an egg with no yolk at all.
BASIC EGG FACTS
The air cell is the empty space between the white and the shell at the large end of the egg.
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.
The size of the air cell is used as one basis for determining grade. In Grade AA eggs, the air cell may not exceed 1/8-inch depth and is about the size of a dime. The air cell of Grade A eggs may exceed 3/16-inch in depth. For Grade B eggs, there is no limit on the air cell size.
As the eggs age, moisture and carbon dioxide escape through the pores of the shell, and air enters to replace them and the air cell becomes larger.
You can see the air cell in the flattened end of a peeled, hard-boiled egg.
Also known as egg white, the albumen accounts for most of an egg's liquid weight, about 67%. It contains more than half the egg's total protein, niacin, riboflavin, chlorine, magnesium, potassium, sodium and sulfur. Egg white tends to thin out as an egg ages because its protein changes in character. That's why fresh eggs sit up tall and firm in the pan while older ones tend to spread out.
Albumen is more opalescent than truly white. The cloudy appearance comes from carbon dioxide. The albumen of older eggs is more transparent than that of fresher eggs because carbon dioxide escapes as the egg ages.
When egg albumen is beaten vigorously, it foams and increases in volume 6 to 8 times. Egg foams are essential for making souffles, meringues, puffy omelets, angel food and sponge cakes.
The yolk or yellow portion makes up about 33% of the liquid weight of the egg. It contains all of the fat in the egg and a little less than half of the protein.
With the exception of riboflavin and niacin, the yolk contains a higher portion of the egg's vitamins than the white. All of the egg's vitamins A, D and E are in the yolk. Egg yolks are one of the few foods naturally containing vitamin D.
The yolk also contains more phosphorus, manganese, iron, iodine, copper, and calcium than the white, and it contains all of the zinc. The yolk of a large egg contains about 59 calories.
Young hens whose egg production cycles are not yet completely synchronized often produce double-yolked eggs. Hens that are old enough to produce Extra Large eggs often produce them, too. Occasionally a hen will produce double-yolked eggs throughout her egg-laying career.
In fertilized eggs, the yolk is the site of embryo formation.
It is the yolk, which is responsible for the egg's emulsifying properties.
The egg's outer covering, accounts for about 9 to 12% of its total weight depending on egg size. The shell is the egg's first line of defense against bacterial contamination.
The shell is largely composed of calcium carbonate (about 94%) with small amounts of magnesium carbonate, calcium phosphate and other organic matter including protein.
Shell strength is greatly influenced by the minerals and vitamins in the hen's diet, particularly calcium, phosphorus, manganese and vitamin D. If the diet is deficient in calcium, for instance, the hen will produce a thin or soft-shelled egg or possibly an egg with no shell at all.
Seven to 17 thousand tiny pores are distributed over the shell surface. A greater number at the large end. As the egg ages, these tiny holes permit moisture and carbon dioxide to move out and air to move in to form the air cell. The shell is covered with a protective coating called the cuticle or bloom. By blocking the pores, the cuticle helps to preserve freshness and prevent microbial contamination of the contents.
Blood spots, also called meat spots are cccasionally found on an egg yolk. Contrary to popular opinion, these tiny spots do not indicate a fertilized egg. Rather, the rupture of a blood vessel on the yolk surface causes them during formation of the egg or by a similiar accident in the wall of the oviduct. Less than 1% of all eggs produced have blood spots.
As an egg ages, the yolk takes up water from the albumen to dilute the blood spot, so in actuality, a blood spot indicates that the egg is fresh. Both chemically and nutritionally, these eggs are fit to eat. The spot can be removed with the tip of a knife, if you wish.
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. In USDA-inspected plants, this date cannot exceed 30 days after the pack date. It may be less through choice of the packer or quantity purchaser such as your local supermarket chain. Laws of their states govern plants not under USDA inspection.
Ropey strands of egg white, which anchor the yolk in place in the center of the thick white. They are neither imperfections nor beginning embryos.
The more prominent the chalazae, the fresher the egg. Chalaza do not interfere with the cooking or beating of the white and need not be removed, although some cooks like to strain them from stirred custard.
Eggshell and yolk color may vary, but color has nothing to do with egg quality, flavor, nutritive value, cooking characteristics or shell thickness.
Several factors influence the size of an egg. The major factor is the age of the hen. As the hen ages, her eggs increase in size.
The breed of the hen, from which the egg comes is a second factor. Weight of the bird is another. Environmental factors that lower egg weight are heat, stress, overcrowding and poor nutrition. All these variables are of great importance to the egg producer. Even a slight shift in egg weight influences the size classification and size is one of the factors considered when eggs are priced. Careful flock management benefits both the hens and the producer.
Egg sizes are Jumbo, Extra Large, Medium, Small and Pee Wee. Medium, Large and Extra Large are the sizes most commonly available. Sizes are classified according to the minimum net weight expressed in ounces per dozen.
Classification determined by interior and exterior quality and designated by letters - AA, A and B. In many egg-packing plants, the USDA provides a grading service for shell eggs. Its official grade shield certifies that the eggs have been graded under federal supervision according to USDA standards and regulations. The grading service is not mandatory. Other eggs are packed under state regulations, which must meet or exceed federal standards.
In the grading process, eggs are examined for both interior and exterior quality and are stored according to weight (size). Grade quality and size are not related to one another. In descending order of quality, grades are AA, A and B.
There is no difference in nutritive value between the different grades.
Because production and marketing methods have become very efficient, eggs move so rapidly from laying house to market that you will find very little difference in quality between Grade AA and A. Although grade B eggs are just as wholesome to eat, they rate lower in appearance when broken out. Almost no Grade B eggs find there way to the retail supermarket. Some go to institutional egg users such as bakeries or food service operations, but most go to egg breakers for use in egg products.
Grade AA: A 'Grade AA' egg will stand up tall. The yolk is firm and the area covered by the white is small. There is a large proportion of thick white to thin white.
Grade A: A 'Grade A' egg covers a relatively small area. The yolk is round and upstanding. The thick white is larger in proportion to the thin white and stands fairly well around the yolk.
Grade B: A 'Grade B' egg spreads out more. The yolk is flattened and there is about as much (or more) thin white as thick white.
Eggs can be incubated and then develop into chicks. Fertile eggs are not more nutritious than non-fertile eggs, do not keep as well as non-fertile eggs and are more expensive to produce. Fertile eggs may contain a small amount of male hormone, but there are no known advantages.
True free-range eggs are those produced by hens raised outdoors or that have daily access to the outdoors. Due to seasonal conditions, however, few hens are actually raised outdoors. Some egg farms are indoor floor operations and these are sometimes erroneously referred to as free-range operations. Due to higher production costs and lower volume per farm, free-range eggs are generally more expensive. The nutrient content of eggs is not affected by whether hens are raised free-range or in floor or cage operations.
Eggs from hens fed rations having ingredients that were grown without pesticides, fungicides, herbicides or commercial fertilizers. No commercial laying hen rations ever contain hormones. Due to higher production costs and lower volume per farm, organic eggs are more expensive than eggs from hens feed conventionally. The nutrient content of eggs is not affected by whether or not the ration is organic.
How recently an egg was laid has a bearing on its freshness but is only one of many factors. The temperature at which it is held, the humidity and the handling all play their part. These variables are so important that an egg one week old, held under ideal conditions, can be fresher than an egg left at room temperature for one day. The ideal conditions are temperatures that don't go above 40 degrees F and a relative humidity of 70 to 80%.
Proper handling means prompt gathering, washing and oiling of the eggs within a few hours after laying. Most commercially produced eggs reach supermarkets within a few days of leaving the laying house. If the market and the buyer handle them properly, they will still be fresh when they reach the table.
It is not true that freshness can be judged by placing an egg in salt water. A carefully controlled brine test is sometimes used to judge shell thickness of eggs for hatching purposes but has no application to freshness of table eggs.
How important is freshness? 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 boil eggs that are at least a week old, you'll find them easier to peel after cooking and cooling than fresher eggs.
What is food borne illness?
The way food is processed and prepared is important because all foods have the ability to carry microorganisms (like bacteria and viruses) or toxins that can cause illness. If microorganisms or toxins are introduced to food, or if bacteria are allowed to grow in or on food without being killed (usually by heat) before eating, food borne illness can result. Common symptoms of food borne illness include nausea, vomiting, diarrhea, cramps and headache.
How safe are eggs?
The risk of getting a food borne illness from eggs is very low. However, the nutrients that make eggs a high-quality food for humans are also a good growth medium for bacteria. In addition to food, bacteria also need moisture, a favorable temperature and time in order to multiply and increase the risk of illness. In the rare event that an egg contains bacteria, you can reduce the risk by proper chilling and eliminate it by proper cooking. When you handle eggs with care, they pose no greater food-safety risk than any other perishable food.
The inside of an egg was once considered almost sterile. But, over recent years, the bacterium Salmonella enteritidis (Se) has been found inside a small number of eggs. Scientists estimate that, on average across the U.S., only 1 of every 20,000 eggs might contain the bacteria. So, the likelihood that an egg might contain Se is extremely small - 0.005% (five one-thousandths of one percent). At this rate, if you're an average consumer, you might encounter a contaminated egg once every 84 years.
Other types of microorganisms could be deposited along with dirt on the outside of an egg. So, in the U.S., eggshells are washed and sanitized to remove possible hazards. You can further protect yourself and your family by discarding eggs that are unclean, cracked, broken, or leaking and making sure that you and your family members use good hygiene practices, including properly washing your hands and keeping them clean.
Are eggs the only source of Salmonella bacteria?
No, Salmonella bacteria are widely found in nature and easily spread. The bacteria can be found in the intestinal tract of animals, birds, reptiles, insects and people. While the egg itself may not be contaminated when you buy it, it can become contaminated from various sources, such as hands, pets, other foods and kitchen equipment, too.
Doesn't the eggshell protect an egg from bacteria?
Yes and no. The egg has many natural, built-in barriers to help prevent bacteria from entering and growing. These protect the egg on its way from the hen to your home. Although it does help, the porous shell itself is not a foolproof bacterial barrier. For further safety, government regulations require that eggs be carefully washed with special detergent and sanitized. Then, the hen's original protective shell coating is generally replaced by a thin spray coating of a tasteless, odorless, harmless, natural mineral oil. A shiny shell indicates oiling, rather than an unsafe or old egg.
Other protective barriers include the shell and yolk membranes and layers of the white, which fight bacteria in several ways. The structure of the shell membranes helps prevent the passage of bacteria. The shell membranes also contain lysozyme, a substance that helps prevent bacterial infection. The yolk membrane separates the nutrient-rich yolk from the white.
In addition to containing antibacterial compounds such as lysozyme, layers of the white discourage bacterial growth because they are alkaline. The thick white discourages the movement of bacteria. The last layer of white is composed of thick ropey strands, which have little of the water that bacteria need but a high concentration of the white's protective materials. This layer holds the yolk centered in the egg where it receives the maximum protection from all the other layers.
Are Salmonella bacteria most likely to be found in the egg's white or yolk?
Bacteria, if they are present, are most likely to be in the white and will be unable to grow, mostly due to lack of nutrients. As the egg ages, however, the white thins and the yolk membrane weakens. This makes it possible for bacteria to reach the nutrient-dense yolk where they can grow over time if the egg is kept at warm temperatures. But, in a clean, uncracked, fresh shell egg, internal contamination occurs only rarely.
Does a blood spot mean an egg is contaminated?
No. You can't see bacteria with the naked eye. Blood or meat spots are occasionally found on an egg yolk and are merely an error on the part of the hen.
Are the twisted, ropey strands of egg white safe?
Yes. These strands are the chalazae, which anchor the yolk in the center of the thick white.
What will happen if I eat an egg containing Salmonella?
If an egg containing Salmonella has been kept refrigerated and someone who uses good hygiene practices serves it to you immediately after proper cooking, you'll simply have a nutritious meal. If the eggs have been improperly handled, though, you might experience the food borne illness called salmonellosis. You could have symptoms of abdominal cramps, diarrhea, nausea, vomiting, chills, fever and/or headache within 6 to 72 hours after eating. The symptoms usually last only a day or two in healthy people but can lead to serious complications for the very young, pregnant women, the elderly, the ill and those with immune system disorders.
What usually causes salmonellosis?
Salmonellosis outbreaks are most often associated with animal foods, including chicken, eggs, pork and cheese, but has also been reported related to cantaloupe, tomatoes, alfalfa sprouts, orange juice and cereal among other foods. Human carriers play a big role in transmitting some types of slamonellosis. Salmonella bacteria can easily spread from one food to another, too.
The majority of reported salmonellosis outbreaks involving eggs or egg-containing foods have occurred in food service kitchens and were the result of inadequate refrigeration, improper handling and insufficient cooking. If not properly handled, Salmonella bacteria can double every 20 minutes and a single bacterium can multiply into more than a million in 6 hours. Properly prepared egg recipes served in individual portions and promptly eaten are rarely a problem. You can ensure that your eggs will maintain their high quality and safety by using good hygiene, cooking, refrigeration and handling practices.
What is being done about Salmonella in eggs?
The egg industry, the public health community and government agencies have been working diligently to deal with Salmonella enteritidis.
Egg industry programs start by keeping breeder flocks free from Salmonella. Ongoing research is dedicated to discovering how Se gets into flocks and how it might be blocked. The industry also uses strict quality-control practices and sanitation procedures all through production, processing and preparation. This includes testing chicks to be sure they're free of Salmonella, bio-security (such as washing and sanitizing not only the eggs, but facilities, too) and other measures. To block Se from multiplying in the egg in the rare event it's present, eggs are held at cool temperatures following packing and throughout transportation. Important, too, are industry education programs, which encourage food preparers to use safe food-handling practices.
Along with state representatives, the United States Department of Agriculture (USDA) and the Food and Drug Administration (FDA) are developing new national standards with the aim of reducing and eventually eliminating egg-related salmonellosis. The strategies will include a scientific, risk-based, farm-to-table plan covering production, processing, transportation, storage, retail handling, and delivery. The plan will also include education on the responsibilities of consumers, inspectors and food handlers at each level.
EGGS AND GOOD HEALTH
For many years, eggs have gotten a bad rap as a forbidden food because of their cholesterol content. The mere mention of cholesterol conjured up fear and was enough to banish eggs entirely from the diets of many Americans. No cholesterol was the most important benefit trumpeted in advertising and on the labels of many food products.
Today, thanks to years of research, we know more than ever about the relationship between diet, lifestyle and good health. There is growing evidence that diet and health relationships are a function of both what is in the diet and what is missing from it. It is also becoming clear that many of our perceptions about various dietary factors are inaccurate. For example, when it comes to dietary cholesterol, many people believe that it is an extremely important factor in high blood cholesterol. Studies have now shown that many people on a low-fat diet can eat one or two eggs a day without measurable changes in their blood cholesterol levels. As reported in a recent publication, Dr. Wanda Howell and colleagues at the University of Arizona conducted a statistical analysis of 224 dietary studies carried out over the past 25 years investigating the relationship between diet and blood cholesterol levels in over 8,000 subjects. What these investigators found was that saturated fat in the diet, not dietary cholesterol, is what influences blood cholesterol levels the most [Howell et al. 1997. Am J Clin Nutr. 65:1747-64.1.]. Therefore, the results of this meta-analysis indicate that for most healthy people, saturated fat is a greater concern than dietary cholesterol, and that eggs can readily fit into a heart-healthy, nutritious and enjoyable dietary pattern.
You love eggs and want them to be part of your diet. That's fine by many nutrition experts, who believe that eggs fit into a healthy, well-balanced eating plan. A large egg contains 4.5 grams of fat (1.5 of which is saturated fat), and 213 milligrams of cholesterol, 22 percent less than previously though based on a 1989 study. Additionally, eggs contain 70 calories each.
An egg is one of nature's most nutritious creations. Eggs are protein-rich, low in sodium, and contain vitamins and minerals. In addition, eggs are inexpensive, delicious, and easy to prepare. There is no need to avoid eggs on a heart-healthy diet. Even cholesterol-lowering diets allow moderate amounts of whole eggs. There is no limit on egg whites, since they're cholesterol and fat-free.
Here are some important egg tips:
Use only properly refrigerated, clean, shelled, fresh, grade AA or A eggs.
Buy eggs from refrigerated cases. Always refrigerate eggs at home.
Store eggs in the carton on a shelf in the refrigerator to ensure freshness.
Eggshell and yolk color may vary, but color has nothing to do with egg quality, flavor, nutritive value, cooking characteristics or shell thickness.
Poach eggs instead of frying to cut back on fat, or use non-stick pans or non-stick vegetable spray to reduce fat when preparing eggs.
Prepare and serve eggs with low-fat foods such as vegetables, fruits, whole grain breads, and low fat or skim-milk cheeses.
Serve egg dishes promptly or keep them refrigerated.
FASCINATING EGG FACTS FOR KIDS
American Chickens Came From Where?
Scientists say that there were chickens in America long ago. But, these chickens weren't the same kinds of chickens that lay our eggs today. Historians believe that the first chickens related to today's egg layers were brought to America by Columbus' ships. The chicken breed that lays most of the eggs we eat is the Single-Comb White Leghorn. The name Leghorn comes from a city in Italy called Livorno in Italian. Christopher Columbus was Italian. He came from the town of Genoa, Italy, which is also famous for salami. But, Columbus' wife was Spanish and the couple lived in Spain for some time. Queen Isabella and King Ferdinand of Spain paid for his voyage. Columbus set sail from Palos, Spain on August 3, 1492. He brought the hens along on this second voyage the next year. The laying hens first supplied eggs and then chicken meat for the hungry crew.
Time to Lay an Egg
The actual time it takes for a hen to make an egg and lay it is 24 to 26 hours. Then the hen rests about 30 minutes or so before starting to make another one. In addition to resting about 1/2 hour each time an egg is laid, some hens rest about every 3 to 5 days and others rest about every 10 days. Some hens hardly rest at all. The resting time increases the total time to lay an egg. Altogether, with all the resting time, the average hen lays about 5 eggs a week (52 weeks in a year times 5 eggs a week = 260 eggs a year).
What Shape is an Egg?
There are a lot of interesting shapes- some natural, some manmade. For example, a dinner plate and a wheel on a bike or a skate are round circles. A ball or an orange is a sphere, a circle that has depth. Tree trunks, soda straws and the tubes that hold paper towels are cylinders. You might eat a scoop of ice cream in a cone or ride on a road that has safety cones set out. Maybe you had a slice of pizza or a slice of pie shaped like a triangle at lunch today. You can walk on a sidewalk made up of sections that are squares. A square with length, width and height is called a cube. Your television set is probably shaped like a cube and some freezer trays make little blocks of ice that are cube shaped. Usually writing paper is a rectangle and so is an envelope. You can probably find many things around you that are these shapes and other shapes, too. While you're looking around at shapes, can you think of the name for the shape of an egg?
If you said an egg is oval, you're right! The fancy math words to describe an egg shape are oblate or spheroid. The word spheroid means that an egg is like a sphere, but not exactly a sphere. That's because an egg isn't perfectly round. The word oblate means that the poles of the egg are flattened or with one end larger than the other. Now that you know this, can you draw an egg?
To draw an egg, you can start with a circle. Then, pretend that it's a round water balloon. You can pull on the top and bottom of the balloon (use your pencil to stretch out the ends, make them longer). Or, you can push in on the sides (move the lines forming the sides closer toward the center). Either way you'll get an oval that's like an egg.
COOK UP A STORM
Have you ever seen a chef's hat? It's called a toque (say this like tow with a hard k on the end). A toque is white, stands up tall and has about 100 pleats. Some cooks say that the pleats stand for all the ways you can cook an egg. Can you think of 100 ways to make eggs?
Many of the 100 ways to cook eggs are just different ways of using the basic methods of cooking eggs. The basic methods are:
Fried (cooked in a pan on a burner)
Over-easy (turned over in the pan to cook both sides, with the second side cooked lightly)
Over-hard (turned over in the pan to cook both sides, with the second side cooked as much as the first)
Sunny-side up (cooked on one side only in a pan with a lid)
Based (cooked with the cooking fat spooned over the top)
Steam-based (cooked in a pan with a lid and a little water to make steam)
Scrambled (beaten with milk and cooked in a pan on a burner while the cook stirs)
French Omelet (beaten with water, cooking in a pan on a burner until it's a circle, then folded or rolled)
Puffy Omelet (made with separately beaten egg whites and yolks so it has lots of air, then cooked in a pan both on a burner and in the oven)
Frittata and Tortilla (Italian and Spanish omelets cooked with all the ingredients in the omelet, cooked in a pan on a burner and sometimes flipped over in the pan to cook the second side, covered with a lid to finish cooking, finished in the oven under the broiler, or made like a French omelet)
Hard-cooked (cooked in very hot water until the white and yolk are both solid)
Soft-cooked and Coddled (cooked in very hot water until the white is set and the yolk starts to thicken but is not hard)
Poached (cooked out of the shell in simmering water or another liquid)
Baked (eggs alone or eggs broken into a sauce or a nest of other foods and baked)
Oven-baked (baked in a dish in the oven)
Range-top-baked ("baked" in a pan with a lid on a burner)
Baked (eggs beaten with milk and other ingredients and baked in the oven)
Sweet (eggs beaten with milk, sugar and flavorings)
Cup custard (baked in a small glass cup)
Pie (baked in a pie plate with a crust, crumbs or another food on the bottom)
Pudding (custard ingredients stirred together with bread, rice, tapioca, or other foods and baked in small glass cups or a casserole dish)
Savory (eggs beaten with milk and other foods)
Quiche (a custard pie baked in a pie plate or quiche dish with a crust, crumbs or another food on the bottom and unsweet ingredients, like vegetables or cheese, instead of sugar in the custard)
Timbale (a little quiche baked in a small glass cup, usually without a crust)
Strata (an unsweet custard with layers of bread and other grain food plus flavoring foods, usually baked in a casserole)
Soft, stirred (eggs beaten with milk, sugar and flavorings then cooked in a pan on a burner until it's a thick, pourable sauce)
Meringue (beaten egg whites and sugar)
Hard or Swiss (dried in an oven until all the liquid is gone)
Soft or Pie (baked or dried in an oven until it's marshmallowy)
Italian or boiled frosting (cooked in a pan on a burner until it's marshmallowy and spreadable)
Souffle (a sauce plus separately beaten egg whites and yolks and flavoring foods)
Hot (flavored with sweet or savory foods and baked in the oven until browned and puffy)
Cold (usually flavored with sweet foods, mixed with gelatin and chilled until set)
Sauce or Dressing
Mayonnaise dressing (oil, lemon juice or vinegar and seasonings thickened and held together by egg yolks)
Hollandaise sauce (butter, lemon juice or vinegar and seasonings and held together by egg yolks)
Caesar dressing (oil, vinegar, garlic and other seasonings thickened and held together by eggs)
Information adapted from (American Egg Board) andwww.incredibleegg.org.
To receive a certificate of training hours you must complete a quiz based on the material above. You are required to get all questions correct. If you do not get 100% on the quiz the first time, you may take it over again. The results of the quiz will be emailed to Mid Michigan Child Care Food Program. When we receive the results of your quiz, a certificate of training completed will pop up that you can print. A copy of the certificate will also be emailed to you.
Shell: The color comes from pigments in the outer layer of the shell and may range in various colors from white to deep brown. The breed of hen determines the color of the shell. Breeds with white feather and ear lobes lay white eggs; breeds with red feathers and ear lobes lay brown eggs. White eggs are most in demand among American buyers. In soem part of the country, however, particularily in New England, brown shells are preferred. Since brown-egg layers are slightly larger birds and require more food, brown eggs are usually more expensive than white.
White: Egg albumen in raw eggs is opalescent and does not appear white until it is beaten or cooked. A yellow or greenish cast in raw white may indicate the presence of riboflavin. Cloudiness of the raw white is due to the presence of carbon dioxide, which has not had time to escape through the shell, thus indicates a very fresh egg.
On very rare occasions, a hard-boiled egg white may darken to a caramel shade due to a high amount of iron in the cooking water. Using fresh eggs and cooling them quickly after cooking helps to prevent this darkening.
Yolk: Color depends on the diet of the hen. If she gets plenty of yellow-orange plant pigments known as xanthophyllis, they will be deposited in the yolk. Hens fed mashes containing yellow corn and alfalfa meal lay eggs with medium yellow yolks, while those eating wheat or barley yield lighter-colored yolks. Natural yellow-orange substances such as maigold petals may be added to light-colored feeds to enhance yolk color. Artificial color additive are not permitted.
Sometimes there is a greenish ring around hard-boiled egg yolks. This is the result of sulfur and iron compounds in the egg reacting at the surface of the yolk. It may occur when eggs are overcooked or when there is a high amount of iron in the cooking water. Although the color may be a bit unappealing, the eggs are still wholesome and nutritious and their flavor is unaffected. Greenish yolks can best be avoided by using the proper cooking time and temperature and by rapidly cookign the cooked egg.