Good Eats - From the Garden to Your Table.

Phil says: A hen usually lays only one egg a day, so imagine all the birds required to produce the 72 billion eggs Americans consume each year. Cluck, cluck!

No wonder eggs are so popular: they pack a powerful nutritional punch. The yolk naturally contains zinc and vitamins D, E, and A. The white (called the albumen) is rich in protein, riboflavin, magnesium, potassium, sodium, sulfur, and niacin. It's true that eggs are high in cholesterol: one egg has about 215 milligrams—and the recommended daily allowance (RDA) is just 300 milligrams. With so many people concerned about cholesterol count, it's not surprising that egg white omelets have become such a popular option on restaurant menus.

Each week I get dozens of emails asking all sorts of questions about eggs. Consumers are understandably confused by all the different "varieties" available—not to mention by the variations in price. Let me try to, er, egg-splain a few things so you will know what you're buying.

First, never pay more for brown eggs! In terms of nutrition, white and brown ones are identical; the only difference is that white eggs come from hens with white feathers, and brown ones from hens with red feathers. But inexplicably, the darker eggs can cost an extra 50 cents or more a dozen.

Secondly, just as you peer inside a carton to make sure the eggs are intact, you should look closely at the outside too. Egg cartons are covered with more descriptive terms than just about any other food, so you need to know what those terms mean and which are worth the extra cost.

Watch for these claims when buying your next carton of eggs:

Hormone-free: It may as well read "rip-off"! Because the use of hormones in poultry has been banned since the 1960s, all eggs are by law hormone-free. If a carton offers this claim alone, you're wasting your money if you pay extra for it.

Natural: This is another meaningless term. According to regulations from the U.S. Department of Agriculture and the Food and Drug Administration, no additives or colors can ever be added to eggs.

Cage-free or free-roaming: Over 90 percent of hens are raised in cages that are between 48 and 68 square inches. Birds that are cage-free or free-roaming are not caged; however, they likely were still raised within the confines of a small building and generally do not have access to the outdoors. So this isn't much of a distinction and often not worth the higher price.

Free-range: This is another misunderstood term. All it means is that hens have access to an outdoor area, which could mean anything from a concrete paved slab to a beautiful grassy pasture. There is no guarantee that the hens avail themselves of the great outdoors. Because of their more relaxed living conditions, these hens produce fewer eggs, making those eggs more costly to produce—and that cost is passed on to the consumer. But free-range eggs generally have the same nutritional content as other eggs—so know that before you pay up for them.

Grass-fed: There is no USDA-approved definition of this term when it comes to hens. Farms touting grass-fed egg-laying hens claim their hens are as close to being "wild" as possible. Grass-fed hens are usually allowed to roam freely, so they eat a variety of things found in their natural habitat: grass, bugs, and whatever animals they might catch and kill. All of these (individually and together, including vegetation) contain adequate protein. However, because this term is not regulated by the USDA, unless you know your supplier's farming practices this labeling is largely meaningless.

Certified humane: For a farm to make this claim, it must meet specific criteria: hens may not be caged; their feed must be vegetarian and contain no antibiotics; and the birds need to live in a natural environment that allows for behaviors like preening and scratching. I find these eggs to be among the most flavorful. Though a bit more expensive, these are the ones I buy.

Fertile: These are eggs that, when incubated, will develop into chicks. They are no more nutritious than other eggs and usually cost more. Usually fertile eggs are cage-free and come from hen houses where roosters roam as well, which some consumers believe is a more natural habitat. As for taste, it's negligible—once cooked, only a true egg aficionado would taste any difference. Be aware that fertile eggs are also much more perishable. Check the expiration date carefully, and be sure to handle them properly and cook thoroughly.

Rich in omega-3s: Omega-3s are a type of unsaturated fatty acid essential for healthy human metabolism that the body cannot produce. This type of fatty acid is thought to benefit the cardiovascular system, reduce inflammation in the body, and reduce risk factors for chronic diseases, such as cancer, arthritis, and heart disease. Many egg cartons now promote the fact that the eggs contain these fatty acids, the result of feeding hens a diet high in omega-3s which are then passed through to the eggs. It's probably worth paying extra for these if you do not eat other omega-3-rich foods, such as salmon, tuna, halibut, mackerel, sardines, walnuts, and flaxseed.

USDA-certified organic: This means that the hens have eaten only organic feed and grain grown without fungicides, herbicides, commercial fertilizers, or pesticides, and that their diet has contain no animal or poultry byproducts. The hens also have not received any antibiotics or growth hormones, and they've been allowed access to the outdoors. There is some debate about how the nutritional content compares to other eggs, which are more expensive because of lower output per hen and higher production costs.

Does Size Matter?

Generally, egg size reflects the age of the hen: the older she is, the larger her egg. Breed, weight, and living conditions (such as heat, stress, overcrowding, or poor nutrition) can also affect size. Extra-large, large, and medium are the most common varieties, but you can also find jumbo, small, and peewee.

Egg grades—which include AA, A, and B—refer to the ratio and quality of white to yolk and to the condition of the shell. Grade AA and A eggs have thicker whites; firmer, more round yolks; and cleaner shells than Grade Bs. Nutritionally speaking, however, eggs are the same regardless of grade. So if you're paying up for a bigger egg, you're buying size and nothing more.

Store Smart—and Save!

Properly refrigerated, eggs can keep up to one month beyond the "best before" date printed on carton. Keep them stored inside the carton, securely fastened. Eggshells have thousands of tiny pores; never store eggs in an open basket or box, as they will absorb odors from other foods. Also, though it may sound counterintuitive, don't keep your eggs in the special egg unit on the inside door of your refrigerator. Though it may be handy, it actually prevents proper airflow to your eggs.

Want to know how to get the most for your food dollar? Send your questions to me at plempert@supermarketguru.com.