Brown eggs and white eggs differ only in shell color, which comes from the breed of hen. USDA FSIS says their nutrient levels aren't significantly different, and USDA's egg grading manual says shell color has no effect on quality and plays no part in grading. Grade, size, freshness and handling matter far more than color.
Key facts
- Shell color is set by the hen's breed; it doesn't change nutrition, flavor or grade (USDA FSIS, USDA AMS).
- USDA grades eggs AA, A or B on interior and shell quality; Grade A is what stores sell most.
- Size is a minimum weight per dozen: Large eggs weigh at least 24 oz (680 g) a dozen.
- On USDA-graded cartons, "free range" means cage-free hens with continuous outdoor access during the laying cycle (USDA AMS).
- US eggs are washed, so FDA requires them to be kept at 45°F or colder from 36 hours after laying; at home, keep them at 40°F or below.
What is the difference between brown and white eggs?
The only built-in difference between brown and white eggs is the color of the shell. USDA FSIS says the breed of hen determines shell color and that nutrient levels in white and brown eggs aren't significantly different. USDA's Agricultural Marketing Service (AMS), which runs the federal egg grading program, puts it plainly in its Egg-Grading Manual: shell color doesn't affect egg quality and isn't a factor in the U.S. standards and grades.
What does change an egg is its grade, its size and how fresh it is. FSIS explains that an egg loses moisture and its air cell grows as it ages, whatever the shell color. A white egg and a brown egg of the same grade and size can be used the same way in any recipe.
Where do brown eggs come from?
Brown eggs come from breeds of hens that lay brown-shelled eggs; white eggs come from breeds that lay white shells. The AMS grading manual notes that most commercial laying hens in the US are White Leghorns, chosen largely because they lay white-shelled eggs, while brown eggs are preferred in some regions. Other breeds lay other colors: FSIS says Araucana hens lay eggs ranging from medium blue to medium green.
Are brown eggs healthier than white eggs?
No. FSIS says the nutrients aren't significantly different, and the AMS grading manual says the belief that brown eggs have more food value has no basis in fact. FSIS adds that claims that Araucana eggs are lower in cholesterol are unproven.
Are white eggs bleached?
No. White eggs are white because of the hen's breed. All USDA-graded eggs, white or brown, go through the same washing and sanitizing at the packing plant; the AMS manual describes wash water at least 90°F and a sanitizing rinse, which cleans the shell but doesn't change its color.
What do egg grades mean?
USDA grades describe the quality of the egg inside and the condition of the shell. Grading is a voluntary service that egg producers pay for; AMS acts as an independent third party, and only eggs graded under USDA supervision may carry the USDA grade shield on the carton. Here's how the grades compare, using the AMS manual's standards and FSIS's consumer descriptions:
| Grade | White and yolk | Shell and air cell | Where you'll see it |
|---|---|---|---|
| AA | Thick, firm white; high, round yolk | Clean, unbroken; air cell 1/8 inch or less | Best for frying and poaching, where looks matter |
| A | Reasonably firm white; yolk fairly well defined | Clean, unbroken; air cell 3/16 inch or less | The grade most often sold in stores |
| B | Thinner white; wider, flatter yolk | Unbroken, may be slightly stained | Rarely sold at retail; mostly used for liquid eggs and baking |
Are Grade A eggs pasteurized?
No. A grade describes quality, not a safety treatment. Pasteurized in-shell eggs are a separate product, treated by a process FDA has accepted, and their labels usually say so. FDA requires untreated shell eggs to carry a safe handling statement telling you to keep them refrigerated and cook them until the yolks are firm. More in is it safe to eat raw eggs.
How much does a large egg weigh?
Egg sizes are set by minimum net weight per dozen, not by the size of any single egg. A dozen Large eggs must weigh at least 24 ounces, which works out to an average of at least 2 oz (about 57 g) per egg in the shell. Individual eggs in a carton can vary a little as long as the dozen meets the minimum. These are the size classes FSIS lists:
| Size | Minimum per dozen (oz) | Minimum per dozen (g) | Average per egg, at least |
|---|---|---|---|
| Jumbo | 30 oz | 851 g | 2.5 oz (71 g) |
| Extra large | 27 oz | 765 g | 2.25 oz (64 g) |
| Large | 24 oz | 680 g | 2 oz (57 g) |
| Medium | 21 oz | 595 g | 1.75 oz (50 g) |
| Small | 18 oz | 510 g | 1.5 oz (43 g) |
| Peewee | 15 oz | 425 g | 1.25 oz (35 g) |
Gram figures use 1 oz = 28.35 g (see grams in an ounce). Most US recipes assume Large eggs. If you're swapping in other sizes or other ingredients, see egg substitutes.
What do cage-free, free-range and pasture-raised mean?
When these claims appear on a carton with the USDA grade shield, USDA AMS defines and checks them. Its current policy for graded shell eggs says:
- Cage-free: hens can roam vertically and horizontally in indoor houses, with fresh food and water, litter, protection from predators, and enrichments that let them perform natural behaviors.
- Free-range: hens meet all the cage-free conditions and also have continuous access to the outdoors during their laying cycle. The outdoor area may be fenced or covered with netting.
- Pastured or pasture-raised: AMS doesn't set its own housing standard. For the claim to appear on a USDA-graded carton, the eggs must be currently certified by a nationally recognized certifying body, such as American Humane or Certified Humane, so the details depend on that certifier's standard.
USDA says production claims on graded cartons are source-verified through on-site farm visits, packers must keep eggs from approved flocks separate, and any carton design with the shield must be approved in advance so the label isn't misleading. None of these claims changes shell color, grade or the safe handling rules.
Why are eggs refrigerated in the US?
US eggs are refrigerated because they're washed and because cold slows bacteria. Commercial washing removes most of the cuticle, the thin natural coating on the shell that the AMS manual says is often mistakenly called the "bloom." To keep washed eggs safe, FDA's egg safety rule requires producers to hold and ship eggs at or below 45°F (7°C) starting 36 hours after they're laid.
At home, keep eggs at 40°F (4°C) or colder, in the carton, in the main part of the fridge rather than the door (see what temperature a refrigerator should be). FSIS says a cold egg left at room temperature can "sweat," which helps bacteria move into the egg, so don't leave refrigerated eggs out more than 2 hours. Stored this way, shell eggs keep 3–5 weeks (see how long eggs last).
Should you wash store-bought eggs?
No. FSIS says USDA-graded eggs are already washed and sanitized at the plant under controlled conditions, and washing them at home can pull wash water into the egg through the pores in the shell.
Farm-fresh eggs vs store-bought eggs
The main practical difference with farm-fresh or backyard eggs is that they're often sold unwashed, with the cuticle still on. University of California Cooperative Extension describes that coating as a natural waxy layer with antimicrobial properties for up to about 72 hours, which also slows moisture loss. That doesn't make unwashed eggs free of risk: bacteria can still be on the shell, and FSIS notes Salmonella can be inside an egg before the shell forms.
How to store unwashed farm-fresh eggs
UC Cooperative Extension advises refrigerating all eggs right after they're collected. Keep them at 40°F or below like store-bought eggs. US food safety agencies don't publish counter-storage times for unwashed eggs, so the conservative choice is the fridge.
How to wash farm-fresh eggs
UC Cooperative Extension's guidance for eggs that need cleaning:
- Dry-clean lightly soiled eggs first by brushing off feathers, shavings and dry dirt.
- If you wash, use running water at least 90°F and about 20°F warmer than the egg. Never soak eggs, because standing water can carry bacteria through the shell.
- Dry the eggs fully before refrigerating them.
- Throw out eggs that are cracked, have weak shells, or are soiled with droppings or broken egg.
Washing removes the cuticle, so once eggs are washed they need to stay refrigerated. Whatever the source, cook eggs until the white and yolk are firm, and egg dishes to 160°F (see egg cooking temperatures). To check older eggs, see how to tell if eggs are bad.
Questions people ask
Are brown eggs better than white eggs?
No. USDA says shell color comes from the hen's breed and doesn't affect nutrition, quality or grade. Choose by grade, size, freshness and any production claims that matter to you.
What is the bloom on an egg?
It's the cuticle, a thin natural coating on the shell. Commercial washing removes most of it, which is one reason US eggs are kept refrigerated.
Do farm-fresh eggs need to be refrigerated?
UC Cooperative Extension advises refrigerating all eggs right after collection, and washed eggs must stay cold because washing removes the protective cuticle.
What does Grade A mean on eggs?
Grade A eggs have clean, unbroken shells, reasonably firm whites and a small air cell. It's a quality grade from USDA, not a safety treatment like pasteurization.
How can I check whether my eggs were recalled?
FoodSafety.gov lists current FDA and USDA recalls and public health alerts. Compare the brand, plant number and dates on your carton with the notice and follow its instructions.
Sources
- USDA FSIS: Shell eggs from farm to table
- USDA AMS: Egg-Grading Manual
- USDA AMS: Shell egg grades
- USDA AMS: QAD 709 policy update on shell egg production claims
- USDA: USDA graded cage-free eggs, all they're cracked up to be
- eCFR: 21 CFR 118.4, Salmonella Enteritidis prevention measures (egg refrigeration)
- FDA: What you need to know about egg safety
- University of California Cooperative Extension: Egg handling and food safety
