The Skinny on Eggs

Everything you need to know to decode an egg carton when buying eggs. Plus, how to store and use safely.
Published July 20, 2018

Nutritionally speaking, eggs are hard to beat: they pack protein plus 18 vitamins and minerals into each small, affordable shell. Besides being a nutritional superstar, the egg is a versatile ingredient in the kitchen that can be served up for breakfast, lunch, dinner, or even a snack.

MUST READ: Can You Eat too Many Eggs?

Here is what you should know about buying, storing, and using eggs.


Decoding Egg Carton Labels

Egg marketers have come up with so many ways to describe their product, it’s hard to decipher which terms actually mean something. Use this glossary to crack the code and understand what you’re reading on a carton:

  • Antibiotic-free and hormone-free are disingenuous terms, because almost all eggs sold in the U.S. can make these claims. Egg-laying hens never receive hormones and antibiotics are only administered if they’re sick, and their eggs don’t go to market.

  • Cage-free, free-range, and pastured all describe the way the hens are raised. Cage-free indicates that the birds aren’t kept in cramped cages, but they may still be kept in barns all day, with no access to fresh air. Free-range hens do have access to the outdoors, but “access” means different things to different egg companies. Both these terms have to meet certain standards when they’re accompanied by a USDA shield—without it, the hens’ living situation may vary widely. Pastured eggs come from hens that live free to roam and eat whatever grass and grubs they find. Because there’s no government oversight of this term, look for an explanation on the carton or a “Certified Humane” seal to be sure the term is accurate.

  • Certified organic eggs are nutritionally identical to their nonorganic brethren. They come from hens that eat organic feed and have access to the outdoors, meeting standards overseen by the USDA’s National Organic Program.

  • Color only indicates the breed of the bird. Nutritionally speaking, white and brown eggs are the same.

  • Grading refers to an egg’s quality inside and out, not its nutritional value. U.S. Grade AA eggs have thick, firm whites, pristine yolks, and clean shells. Grade A eggs, the kind you’ll commonly find in stores, have whites that are slightly less firm. And Grade B eggs, which are generally reserved for bakeries or food service companies, have thinner whites, imperfect yolks, and shells that may have stains. Grading is voluntary, and compliance occurs either at the state level or by certified USDA inspectors.

  • Omega-3 enriched eggs come from hens that are fed a special diet containing flaxseed, algae, or fish oil. While eggs naturally contain about 30 mg of the fatty acid, an enriched egg usually offers more than 100 mg.

  • Pasteurized eggs are safe to use in recipes that call for raw eggs. They get heated to a temperature high enough to kill pathogens without cooking the egg.

  • Size measures the weight of a dozen eggs, not the dimensions of each one. Although the eggs may range from jumbo to peewee, you’re most likely to find extra-large, large, and medium. Most recipes call for large eggs.

And what about that mysterious code printed on one end of the carton? It simply shows the date and place where the eggs were packed. The three-digit number on the left notes the date, according to the 365 days of the year (so "035" equals the 35th day of the year, February 4). The code on the right beginning with a "P" is the USDA-assigned number of the packing plant.

Depending on what state you live in, you may also see a “sell by” or “use by” date, which indicates when the eggs are at peak quality. Refrigerated eggs generally remain safe to eat for three to five weeks after purchase.


Buying Eggs Safely from Small Farms

While you might assume that buying eggs at the farmers’ market or from a CSA will ensure better quality, research suggests that eggs from smaller flocks may be more likely to carry bacteria like salmonella. Farms with fewer than 3,000 laying hens are exempt from the FDA’s oversight on food safety issues, so it’s up to each state to determine best practices.

To play it safe:

  • Only buy eggs that have been stored continuously below 45°F.
  • Before buying, open the carton to make sure shells are clean, dry, and intact.
  • Don’t be shy: Ask the farmer about how eggs are handled before coming to market.


How to Choose and Store Eggs

No matter where you buy your eggs, these safe buying and storing guidelines apply:

  • Never buy a cracked egg. If one cracks on the way home, break it into a clean container, cover it, and refrigerate no more than two days.
  • Store eggs in their carton, in the coldest part of the refrigerator—not on the door.
  • Don’t wash eggs before use, which may accidentally draw bacteria into the egg through the shell.
  • Leave refrigerated eggs at room temperature for no more than two hours. As chilled eggs warm up the shells may sweat, which encourages the growth of bacteria.


How to Use Eggs Safely

Safe handling guidelines apply during cooking, too:

  • Always wash your hands before and after handling raw eggs.
  • To avoid cross-contamination, wash utensils, counters, and other surfaces that touch the eggs with hot, soapy water.
  • Unless your eggs are pasteurized, cook them until the yolks are firm.
  • Eggs that crack during hard-cooking are safe to eat.

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