What makes a good egg? There are so many things to consider, especially when egg carton vocabulary seems to grow by the day. What's the difference between free-range and cage-free? What does vegetarian-fed mean to the animals, or to their eggs? It's not just about Medium, Large, Extra-Large, and Jumbo anymore —egg labeling covers all sorts of ground, for people and animals alike. So if you're in an egg-sistential quandary in the grocery aisle, here's a cheat sheet on how to decipher egg dozens.
Egg Sizes and Grades:
These labels are issued by the United States Department of Agriculture (USDA). They're voluntary qualifications by the egg manufacturer or farm. In an eggshell, the following apply.
- Jumbo eggs must be a minimum of 30 ounces per dozen, or an average of 2.5 ounces each.
- Extra Large eggs must be a minimum of 27 ounces per dozen, or an average of 2.25 ounces each.
- Large eggs must be a minimum of 24 ounces per dozen, or an average of 2 ounces each (this is the standard size egg for recipes).
- Medium eggs must be a minimum of 21 ounces per dozen, or an average of 18.4 ounces each.
- Small eggs must be a minimum of 18 ounces per dozen, or an average of 1.5 ounces each.
- Peewee eggs must be a minimum 15 ounces per dozen, or an average of 1.25 ounces each.
There is currently no USDA size standards for eggs from other birds, such as duck eggs, quail eggs and ostrich eggs, although these varieties can be found at many ethnic groceries or small farmers markets.
- US Grade AA eggs are found to have exceptionally thick whites, clean shells, and shallow air cells (those pockets of air at the more blunt point of the egg).
- US Grade A eggs have "reasonably" firm whites. These eggs are most commonly found in stores.
- US Grade B eggs may have blemishes and thinner whites, and are not commonly found in grocery stores but used for industrial purposes.
The eggs found in most grocery stores these days have all sorts of other marketing terms splashed across their cartons, but some phrases are more meaningful than others. Here's what some of the most common labels really mean:
- All-Natural/Farm Fresh: Essentially, this label means that the product is eggs. They may be minimally processed and contain no added ingredients, but they're pretty much just eggs.
- Certified Organic: This voluntary certification is audited and issued by the USDA's Natural Organic Program. For eggs to be certified organic, the hens must be fed an organic, vegetarian diet free of antibiotics and pesticides. They are required to have outdoor access and live in uncaged barns, but the amount of time hens are allowed outdoors is undefined.
Cage-Free/Free-Range/Free-Roaming: These labels convey that the hens are not kept in battery cages, an unfortunate industry standard that keeps hens confined to tiny cages. Typically, when eggs are labeled "free-range" or "free-roaming," the hens have some access to the outdoors, though there's no guarantee they actually end up there, while "cage-free" may or may not involve the option to go outside.
A brief aside on chickens in their natural state: chickens are omnivores, and tend to be barnyard scavengers. They will eat fruits and vegetables, bugs and worms, and table scraps. Commercial hen feed is designed to provide a well-balanced nutrition for egg-laying hens, with protein and calcium. But chickens also enjoy pecking at grasses, plants, and bugs when outdoors.
- Certified Humane: This label is issued and monitored by Humane Farm Animal Care. The birds are uncaged and the organization sets requirements for their living conditions. They also prohibit forced molting through starvation, a technique widely practiced in commercial egg production to increase the number of eggs that hens in their second or third season can lay.
- Animal Welfare Approved: This label, issued by the Animal Welfare Institute, ensures that hens are cage-free, have continuous outdoor access, and have a required amount of space, perches, and nesting boxes per flock. The birds must be allowed to molt naturally, and beak cutting, another industrial standard for egg production, is not allowed.
- Vegetarian-Fed: This label conveys that the hens are fed an all-vegetarian diet with no animal byproducts, as with certified organic eggs. Remember Mad Cow Disease? That's why this label exists, though the safety concerns around animal byproducts in animal feed mostly pertains to animals that are raised for meat and poultry, not eggs. Still, healthy chicken feed can be made all-vegetarian, so if you're playing it safe, keep an eye out for this label.
- Omega-3: Eggs with this label come from hens that are fed a diet which produces omega-3 fatty acids in their yolks—often flaxseeds and occasionally fish oil. Omega-3 fatty acids are thought to help lower cholesterol and can be found in many foods naturally, including eggs. The amount of omega-3 found in eggs with this label vary, and since it is not a required element in nutrition facts, it's tough for everyday shoppers to know exactly how much they're getting. Pro tip: many producers label the amount on their packaging or websites.
Another Note on Labeling: All of the labels mentioned above are voluntary, and often require payment from the organizations who issue them. As a result, even some producers who meet (and exceed!) the safety and welfare requirements sometimes choose not to affix those labels. Small farms, like the ones you might find at your farmers market, might not have the marketing budget to seek out official labeling. But when it's a small operation, the easiest way to find out how their eggs are made is to ask the farm or farmers yourself. For instance, if you're concerned about animal welfare issues such as forced molting, you can ask the farmer how long the hens live there and what methods are used, if any, to increase production in older birds. Or if you're simply curious about what affects the color of their yolks, ask the farmer what his hens have been eating lately (more on that below).
Egg shell color is determined by one thing: the breed of the hen who laid it. White and brown-colored eggs are the most common these days, but some breeds may lay eggs that are pastel green, blue, taupe, or speckled. While the hens chosen for most commercial egg production lay either brown or white eggs, many breeds of heritage hens lay brown and white eggs as well. Egg shell color shouldn't affect how the eggs taste or cook, and there are regional preferences when it comes to color (in the Northeast, for example, brown eggs rule, while most of the rest of the country prefers white).
When a hen lays an egg, it becomes coated in a protective film that prevents many contaminants from becoming absorbed into the egg, since the shell is porous. When eggs are sold in cartons in U.S. supermarkets, this protective cuticle has already been washed off. However, if you are buying eggs direct from a farmer (or in Europe and other parts of the world, where eggs are not typically scrubbed before sale), you may see dirt clinging to shells. This can be brushed off and should not affect the safety of the eggs' interior.
A hen's diet may affect yolk color and quality. Generally, if a yolk is pigmented deep orange, the hen has enjoyed a diet rich in beta-carotenes, from grass and other leafy green plants. As a result, eggs from pastured hens, or hens that have ample access to outdoors and grass, are associated with more orange-pigmented yolks. Some sources have observed anecdotally that yolks from hens that were raised on a diet of plants, worms, and other insects also develop a thicker, creamier consistency and fuller flavor. However, our own tests have shown that in blind tastings, color has very little bearing on flavor.
The USDA recommends eggs be refrigerated as soon as you bring them home, as most eggs sold in cartons in the U.S. have been washed of their protective cuticles. Once an egg is refrigerated, it shouldn't sit out for more than 2 hours, as contaminants and harmful bacteria may start to be absorbed through its porous shell. However, if an egg is never scrubbed of its cuticle, then refrigeration is not necessary before sale or use—that's why you'll sometimes see eggs sold without refrigeration direct from farms or in other countries.
There are several factors that can help determine the freshness of eggs. The USDA recommends storing fresh, uncooked eggs in their shell no more than 3-5 weeks refrigerated. But eggs can be packed into cartons by producers as many as 30 days after they were laid, so technically the sell-by date can be up to 60 days from laying. Here are some clues to finding out how fresh your eggs are.
- "Sell by" date: This is a voluntary label issued by the USDA and is no more than 30 days from the date that the eggs were packed in the carton.
- "Use by" or "Best by" dates: This voluntary label issued by the USDA must be no more than 45 days from the date the eggs were packed in the carton.
To take egg freshness into your own hands, keep in mind that the freshest eggs will have thicker, firm whites and smaller air pockets at their blunt end. This is because as the egg ages, its internal moisture slowly evaporates through the porous shell, increasing the size of the air pocket inside.
Why should you care about egg freshness? It shouldn't affect taste, but it will affect the raw eggs' texture, making fresher eggs better-suited to some preparations over others.
Try the following tests at home to see how fresh your eggs are:
- Place a raw egg in a bowl of water. If it lays flat, then it has a relatively small air pocket and is probably fresh. Eggs that stand upright have a larger air pocket and are thus older. If it starts to float, it's even older.
- Shake the egg. If you can hear or feel the yolk banging against the shell walls, then the white is thinner so the egg is probably older.
Best culinary uses for very fresh eggs:
Poached or fried, because the thick whites will not run as much and the eggs will hold their shape better. It's easy to flip an egg over-easy when the egg whites aren't trying to escape to the edges of the pan! Likewise, poaching eggs becomes a simpler task when the whites encircle the yolk without much help from devices. With fresh eggs on hand, there's no reason not to top that salad, tartine or side with a crispy-edged sunny side-up egg, or to slip a poached egg into soup for extra richness. Check out our foolproof method for poaching eggs for your next eggs Benedict at home.
Best culinary uses for old eggs:
Scrambled, hard-boiled, or for use in dessert and baking recipes, since the eggs will be beaten or boiled in their shell. There's no harm in using older eggs to make a fluffy quiche or frittata, or to fold into scrambled bits in fried rice or noodles. Plus, it's actually easier to peel hard-boiled eggs when the eggs are not as fresh. So help yourself to more egg salads when you've got a carton that's been sitting around for a while in the fridge.
Word to the Wise: If your egg is less than one week old—generally, this will only occur with small producers such as farmers at the farmers market, or eggs from hens that you or your neighbor raised—the shells will be extremely difficult to peel. It's not recommended to try making hard-boiled egg salads or deviled eggs with eggs this fresh. The whites will cling to the shells, and appear like a picked-at mess! Check out more secrets to peeling hard-boiled eggs for Deviled Eggs that aren't cursed.
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