United Egg Producers Certified

Frequently Asked Questions

Animal Care & Egg Production

What are the different types of egg production?

What's the difference between a cage-free and a free-range hen?

Do your egg farmers inject their hens with hormones?

What is beak-trimming?

Are eggs that have the Animal Care Certified eggs coming from vegetarian feed hens?


Egg Processing

What does it mean if I have a United Egg Producers Certified logo on my egg carton?

What is candling?

What is pooling and why is it not recommended?


Egg Quality & Safety

How is egg size determined?

What is grade classification?

What does the date on the egg carton mean?

How does Salmonella infect eggs?

Can shell eggs be pasteurized or irradiated to destroy Salmonella?

Are egg products pasteurized?

Is the appearance of an egg related to food safety?

How is the egg industry working to promote egg safety?


General Consumer Questions

What should you consider when purchasing eggs?

How long are eggs safe to eat after purchase?

How long are eggs that have been refrigerated, safe to eat?

How long are hard cooked eggs that have been refrigerated, safe to eat?

What is a double yolk egg? How are they formed?

Why do eggs have a white string-like attachment on the inner lining of the shell?

Why do some eggs have blood spots?

What are the dark spots in some eggs?

What determines whether an egg is white or brown?

What causes the egg yolk color to vary in shades of yellow?

How should eggs be refrigerated?

I just realized I left the egg carton on the kitchen counter overnight. Are the eggs safe to use?

What is an adequate temperature to cook an egg?

Can raw eggs be frozen?




Animal Care & Egg Production

What are the different types of egg production? [Back to Top]

Many of our egg farmers have multiple systems for egg production and are able to provide their customers with eggs from modern production housing systems (cage), cage-free barns, free-range and organic systems. UEP Certified farmers believe in consumer choice.

Modern Cage Production
This method consists of placing the hens in wire cages with feed and water being provided to each cage. The birds are housed with several hens in each cage, with plenty of space for comfortable movement and easy access to food and water. The cages are arranged in rows which are placed on leg supports or suspended from the ceiling. Water is supplied by individual cup waterers or a long trough outside the cages that extends the length of the row of cages. The feed trough is also located outside the cages and runs parallel to the water trough on the opposite side of each cage and the hens are fed a balanced diet with just the right combination of nutrients to keep them healthy and productive. Housed in cages, birds seldom require medicine and are never fed hormones or steroids. The cages are designed so the eggs will roll out of the cage to a holding area by means of a slanted wire floor. Special tunnel ventilation produces a steady 10mph breeze for lots of fresh air, which fluffs the feathers and carries away body heat as well as manure smells.

Cage-Free Production
Cage-free birds are kept in large heated and air-cooled growing houses where they can roost and socialize freely, participating in their chicken behaviors and pecking orders, and laying their eggs in dark, quiet nests. Hens are required to have at least 1.3 square feet per bird floor space in the henhouse. Their eggs are gathered straight from the nest, placed in a cooler, and then processed. Because cage-free hens are allowed to roam free in the hen house, cage-free production is more labor-intensive and land-intensive which accounts for the higher price of eggs from cage-free hens.

Organic Eggs
Organic Eggs are produced by hens that receive a special diet and special treatment. The hens that lay the organic eggs are also cage-free birds, meaning they are free to roam throughout their henhouse − entering and leaving their nests at will. Hens are required to have at least 1.3 square feet per bird floor space in the henhouse. They also have access to the outdoors when seasonable appropriate. They eat only pesticide-free 100% organic feeds from the day of their birth; neither the hens nor their feed can be subjected to antibiotics, hormones, pesticides or herbicides. If access to pasture is not feasible, flocks must be fed sprouted grains or fresh plants or hay on a daily basis. Their eggs are gathered straight from the nest, placed in a cooler, and then processed.

What's the difference between a cage-free and a free-range hen? [Back to Top]

Cage-free hens are not housed in modern production systems. Usually, cage-free hens live on the floor of a barn or poultry house. The nutrient content of eggs from cage-free hens is the same as those from hens housed in modern production facilities with cages. Free-range eggs (or free-roaming) are eggs from hens that live outdoors or have access to the outdoors. Again, the nutrient content of these eggs is the same as those from hens housed in modern cage or cage-free systems.

Do your egg farmers inject their hens with hormones? [Back to Top]

No, growth hormones are never fed to pullets being grown for egg-laying hens nor during the egg-laying period. We feed our hens a high quality, nutritionally balanced diet made up of mostly corn, soybean meal, vitamins and minerals. The feed is carefully formulated with the proper nutrients to produce quality eggs.

What is beak-trimming? [Back to Top]

UEP Certified guidelines recommend beak trimming for cage and cage-free production only when necessary to prevent feather pecking and cannibalism and only when carried out by properly trained and monitored personnel. Some of the advantages of beak trimming include reduced pecking, reduced feather pulling, reduced cannibalism, better feather condition, less fearfulness, less nervousness, less chronic stress and decreased mortality.

Are eggs that have the Animal Care Certified eggs coming from vegetarian feed hens? [Back to Top]

The feed we give our hens is balanced with ingredients made up mostly of corn, soybean meal, vitamins and minerals.  The feed is an amino acid balanced diet that is essential and has been recommended by a nutritionist. Egg producers do not feed hens animal byproducts as an ingredient.

Egg Processing

What does it mean if I have a United Egg Producers Certified logo on my egg carton? [Back to Top]

To identify eggs in the marketplace as having been produced by UEP Certified companies, a logo has been developed and made available to our egg farmers for use on their egg packaging. A Certified company may use the UEP Certified logo only on those eggs or egg products produced by UEP Certified companies.

What is candling? [Back to Top]

Candling is the process of inspecting the quality of the interior and exterior of each egg, both by the human eye and with a computer. This function occurs after the egg has been washed and the shell sealed with a protective mist of mineral oil and water. Electronic candling systems help ensure that our eggs are clean and crack-free, and rapid processing on automated equipment helps preserve freshness.

What is pooling and why is it not recommended? [Back to Top]

The pooling of eggs is a common practice where eggs are broken out of their shell, mixing egg white and yolk, then held together in large quantities. This practice removes the egg's natural barriers and creates a nutrient-rich medium that is ideal for bacterial growth. Lack of washing hands and cutting boards with warm, soapy water is another contributing factor in approximately one third of the U.S. food borne illness outbreaks reported by the Centers for Disease Control and Prevention (CDC).

Egg Quality & Safety

How is egg size determined? [Back to Top]

Size represents the minimum net weight per dozen. In descending order, egg sizes are Jumbo (30 ounces per dozen), Extra Large (27 ounces), Large (24 ounces), Medium (21 ounces), Small (18 ounces) and Peewee (15 ounces). Medium, Large and Extra Large are the sizes most commonly available because these are the sizes hens most often lay.

Size classifications were established by the U.S. Department of Agriculture and have been the same for decades. You may find some eggs in a dozen that seem a bit larger or smaller than the others, though. Hens operate according to nature and seldom produce perfectly matched cartonsful. No matter how big or small the eggs look, however, you’re getting your money’s worth. Automatic weighing equipment is programmed to provide at least the minimum weight, or more.

What is grade classification? [Back to Top]

Grade classification is determined by the interior and exterior quality of the egg at the time it is packed. In the grading process, eggs are examined for both interior and exterior quality before they’re sorted according to weight (size). Grade quality and size are not related to one another. In descending order of quality, grades are designated AA, A and B. More detailed information about egg grading is available at http://www.incredibleegg.org/g_grading.html.

What does the date on the egg carton mean? [Back to Top]

Egg cartons with the USDA grademark 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, but are still safe to eat. On cartons with the USDA grademark, this date can not exceed 30 days after the eggs were packed in the carton.  Depending on the retailer, the expiration date may be less than 30 days. Eggs packed in cartons without the USDA grademark are governed by the laws of their states. 

Julian date: usually located on the short side of the carton and represents the consecutive days of the year with the number 001 as January 1 and December 31 as 365.

How does Salmonella infect eggs? [Back to Top]

Salmonella bacteria are found in the intestinal tracts of animals, birds, reptiles, insects and humans. Salmonella may be found on the outside of the egg shell before the egg is washed or it may be found inside the egg if the hen was infected. It is estimated that one egg in 20,000 eggs may contain Salmonella which is a 0.005% contamination rate. Eggs contain natural antimicrobial substances in the egg white, and all eggs are washed and sanitized before they are packed. Egg recipes properly prepared in individual servings and promptly eaten are rarely a problem.  Inadequate refrigeration, improper handling and insufficient cooking are all factors that have contributed to disease outbreaks. Salmonella is destroyed by heat. Eggs that have been handled and cooked properly should not cause human illness.

Can shell eggs be pasteurized or irradiated to destroy Salmonella? [Back to Top]

A processor can pasteurize shell eggs if the FDA has approved the process. Pasteurized shell eggs are available in some areas in the U.S. Shell eggs have recently been approved for irradiation by the US Food and Drug Administration but are not yet available.

Are egg products pasteurized? [Back to Top]

All egg products are required by law to be pasteurized.  Approximately one third of all eggs produced in the US today are broken and further processed to make egg products which are sold as retail or foodservice items or ingredients for commercial food manufacturers. These may be whole liquid eggs, egg whites, or egg yolks, and may be liquid, frozen or dried. The safety of egg products is regulated by the Food Safety Inspection Service of the USDA and is ensured by mandatory pasteurization to destroy potentially harmful pathogens.  Egg products are readily available for food service facilities to use and offer a convenient alternative to using raw shell eggs when large quantities are needed.

Is the appearance of an egg related to food safety? [Back to Top]

Variation in egg color is due to many factors. A cloudy egg white is a sign that the egg is very fresh. A clear egg white is an indication that the egg is aging. Pink or iridescent egg white indicates spoilage and should not be consumed. A rupture of one or more small blood vessels in the yolk may cause blood spots at the time of ovulation. It does not indicate the egg is unsafe to eat. The color of the yolk varies in shades of yellow depending upon the diet of the hen.  If she eats plenty of yellow/orange plants the yolk with be a darker yellow than if she eats white cornmeal, a colorless diet. A green ring on a hard cooked yolk is the result of overcooking and is caused by sulfur and iron compounds in the egg reacting on the yolk's surface. The green color can also be caused by a high amount of iron in the cooking water.  Scrambled eggs held too long on a steam table or at too high a temperature can also develop a green tint. The green color is safe to eat.


How is the egg industry working to promote egg safety? [Back to Top]

Egg industry programs start by keeping breeder flocks Salmonella free. The National Poultry Improvement Plan, a joint program between the industry and the U.S. Department of Agriculture, is a model program for preventing breeder stock infection.  Ongoing research projects are dedicated to discovering how Salmonella gets into flocks and how it might be blocked. 

A number of farm-level programs such as the United Egg Producer's 5 Star program, apply quality control measures and sanitation procedures all through the production, processing and preparation phases, including testing chicks to confirm their cleanliness and Salmonella free status. By holding eggs at cool temperatures (45°F) during production and transportation stages, producers help to ensure that any Salmonella present will not multiply and fewer bacteria will be available to spread or risk infecting the consumer. The American Egg Board and the Egg Nutrition Center are members of the Partnership for Food Safety Education (www.fightbac.org), a unique industry and government coalition whose purpose is to reduce food borne illness by educating the public about safe food handling practices.

General Consumer Questions

What should you consider when purchasing eggs? [Back to Top]

Always buy eggs from a refrigerated case. Choose eggs with clean, uncracked shells. Don't buy out of date eggs. The USDA grade shield on the carton means that the eggs were graded for quality and checked for weight under the supervision of a trained USDA grader. State agencies monitor compliance for egg packers who do not use the USDA grading service. Remember to always check for the "UEP Certified" logo.

How long are eggs safe to eat after purchase? [Back to Top]

Fresh shell eggs can be stored in their cartons in the refrigerator for four to five weeks beyond the carton's Julian date with minor loss of quality. Once an egg begins to age, it loses moisture through its porous shell and begins to dry. The membranes that hold the egg structure begin to loosen and the yolk may not be anchored in the center of the white once the egg is broken. An older egg would be most appropriate for a mixed dish, a batter or a hard cooked egg which should be easier to peel than a freshly laid egg.

How long are eggs that have been refrigerated, safe to eat? [Back to Top]

Raw eggs maintain their freshness for 4-5 weeks after purchase if kept refrigerated continuously.

How long are hard cooked eggs that have been refrigerated, safe to eat? [Back to Top]

A hard cooked egg can safely be refrigerated for up to one week.

What is a double yolk egg? How are they formed? [Back to Top]

A double yolk occurs in an egg when a chicken releases two yolks into the same shell.  Double yolks are usually produced by young chickens. Their reproductive systems have not fully matured, and they periodically release two yolks instead of one. These eggs are perfectly safe to eat, and are said to bring good luck when you find them. In fact, you may occasionally find an egg with three or even four yolks - if you're lucky!

Why do eggs have a white string-like attachment on the inner lining of the shell? [Back to Top]

The string-like attachment is called the Chalaza. This anchors the yolk in the center of the egg. A prominent Chalaza is the sign of a high quality egg.

Why do some eggs have blood spots? [Back to Top]

Blood spots are caused when tiny blood vessels rupture during the development of the egg. They do not alter the taste or quality of the egg.

What are the dark spots in some eggs? [Back to Top]

Brown hens have not been genetically improved over time like their white counterparts. That's why a brown egg will occasionally have paprika-looking spots of dark red in the egg. These may surprise you, but they are harmless. Scientists report that most of these spots are simply the pigment or coloring from the shell.

What determines whether an egg is white or brown? [Back to Top]

The breed of the chicken determines shell color of an egg.  Because brown chickens are usually larger and require more food to make an egg, brown eggs cost more than white eggs.  In general there is no difference between brown and white eggs.

What causes the egg yolk color to vary in shades of yellow? [Back to Top]

The color of the yolk varies depending upon the amount of corn in the hen's diet.  Thus, a darker yolk usually means a diet that contains more corn or alfalfa in the feed.  Yolk color does not affect nutritive value or cooking characteristics. Egg yolks are a rich source of vitamin A regardless of color.

How should eggs be refrigerated? [Back to Top]

Refrigerate raw shell eggs in their cartons on the middle or lower inside shelf, not on the door, and away from any meat that might drip juices or any raw produce that might contact eggshells. Cover or wrap well any egg mixtures or leftover cooked egg dishes. For all perishable foods, including eggs and egg containing dishes, allow no more than 2 hours at room temperature for preparation and serving, 30 minutes to 1 hour when it's 85°F or hotter without refrigeration.

I just realized I left the egg carton on the kitchen counter overnight. Are the eggs safe to use? [Back to Top]

The general rule is that if food items are at room temperature for more than 2 hours, the safest thing to do is to discard the product. If you leave eggs anywhere that is not refrigerated, the best thing to do is throw those eggs away and buy a new carton.

What is an adequate temperature to cook an egg? [Back to Top]

Egg white coagulates between 144 and 149°F, egg yolk coagulates between 149 and 158°F and whole eggs between 144 and 158°F. Plain whole eggs without added ingredients are pasteurized but not cooked by bringing them to 140°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°F for 15 seconds.  If the eggs are to be used in a recipe with other food items, dilute the eggs with 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°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.

Can raw eggs be frozen? [Back to Top]

Yes, eggs can be frozen.  Egg whites and whole eggs (whites + yolks) that are blended together survive the freeze/thaw process just fine.  Egg yolks frozen without salt or sugar become very rubbery and gelatinous and will be difficult to incorporate into a recipe.  The link attached explains how much salt/sugar should be added to prevent gelation: http://www.incredibleegg.org/f_freezing_eggs.html.