All About Eggs -- Introductory Materials

[eGCI Team]

ALL ABOUT EGGS

Steven A. Shaw

Introductory Materials

Overview

The word "perfect," so overused in food writing, is rarely accurate: how many of the dishes or ingredients described as "perfect" in restaurant reviews are truly ideal and impossible to improve upon?

If there is a perfect food, however, it is surely the egg. From the simple flawlessness of a properly poached egg to the miraculous leavening power of egg-whites folded into a souffle, the egg is always there for us. It can be the star of the film, a supporting actor, or the technical crew -- and it can win an Oscar in any of those roles.

If you have eggs in your larder, you're never without a delicious meal of poached, boiled, scrambled, or fried eggs. If you have just about any additional ingredients on hand, you should be able to produce an omelette, a frittata, a quiche, or a souffle. These aren't just subsistence recipes -- if you make eggs properly, you should be proud to serve these dishes to guests.

This eGCI presentation, "All About Eggs," will cover basic egg theory and technique. In these Introductory Materials, I'll present foundational information about eggs, from nutrition and safety to weights and grades. Then, on Friday, I'll present an egg FAQ, assembled from both personal experience and research. In the units to be presented next Monday, Tuesday, and Wednesday, I'll go over basic egg cookery: boiling, poaching, omelette-making, etc. Finally, next Thursday, my co-instructor Carolyn Tillie is going to present the final unit: sweet and savory souffles.

Bear in mind that, while this class will be somewhat detailed, it really covers only one aspect of the multi-faceted egg, which I'll call "whole-egg cookery." In previous classes, eGCI instructor Jack Lang has covered egg-derived sauces like mayonnaise (in his "Non-Stock-Based Sauces" class) and hollandaise (in his "Cream Sauces" class. We will also not be discussing most of the thousands of applications of eggs in baking and pastry.

Because this class is so tightly focused on eggs as such, I won't present a shopping list. I suggest you acquire at least 4 dozen eggs, however, to get yourself through the next week of the eGCI. Beyond that, as long as you have basic pots, pans, and utensils, you should have no trouble participating in every unit of this class.

In addition to Carolyn Tillie and the eGCI Team, I'd like to thank Rachel Perlow for assisting in the preparation of this class. She's the official "All About Eggs" hand model and did most of the actual cooking while I took the snapshots in her kitchen in New Jersey last weekend. A few additional photos came from the US Department of Agriculture (USDA). For research, I have relied most heavily on the USDA and the American Egg Board (AEB), and for refreshing my memory on the finer points of technique I'm grateful to Julia Child for producing the excellent videocassette series, The Way to Cook, in the mid-1980s.

Eggs and Nutrition

In the USA, at least, eggs suffered an unjust setback in the early 1990s on account of a public and media panic attack about their cholesterol content: a single egg contains most of the USRDA (Recommended Daily Allowance) of cholesterol, and two eggs puts one over the limit. Yet cholesterol in food (dietary cholesterol) does not necessarily translate into cholesterol in the body (serum cholesterol), and the causes of coronary artery disease are varied and complex -- it's not a simple equation where the more cholesterol you eat the more your cholesterol rises and the more your risk of heart disease increases. In fact, the most comprehensive studies done to date have indicated that, in healthy people, there is no connection whatsoever between egg consumption and increased risk of coronary artery disease -- only among diabetics was any correlation found. ("A Prospective Study of Egg Consumption and Risk of Cardiovascular Disease in Men and Women," Hu et al., JAMA.1999; 281: 1387-1394.) The researchers theorized that perhaps whatever small potential adverse effect the cholesterol in an egg could have on the body is counterbalanced by "other nutrients including antioxidants, folate, other B vitamins, and unsaturated fats.''

And what an embarrassment of nutritional riches eggs contain. Looking beyond the cholesterol bugaboo, one can easily see that the egg's perfection is more than just culinary -- it's also the food you want with you on a desert island. It is, according to every source I've found, the most efficient natural protein source available. A whole large egg contains only about 70-75 calories -- it would be nearly impossible to eat enough eggs to make you fat. Nutrient-wise, eggs are teeming with good stuff.

Source: USDA

Eggs and Safety

The bum nutritional rap that eggs got in the '90s was compounded by another erroneous accusation: that eggs are somehow unsafe. It's almost as comical as it is sad to see the way so many people, Americans in particular, handle eggs as though they're toxic substances. People run frantically from the grocery store to the car to the home refrigerator to make certain their eggs don't spend more than a few minutes unrefrigerated, yet in most of the civilized world eggs are sold and stored at room temperature. Americans frequently cook their eggs to death for fear of salmonella, yet only about 1 in 20,000 eggs is likely to be contaminated -- at average rates of consumption, you would encounter a contaminated egg once every 42 years, and you probably wouldn't get sick from eating it (the last estimate I saw was that there is 1 salmonella outbreak per 1 billion eggs consumed). Likewise, while it's always a good idea to "work clean" when cooking, it's somewhat alarming to see people run to wash their hands every time they touch an egg. I'd much rather see everybody who uses a public toilet wash his or her hands.

I'm not going to bog this lesson down with appeals to safety. Certainly, infants, the elderly, and those with compromised immune systems need to be extra careful. If you're interested in the official version, the Centers for Disease Control will happily make you paranoid about eggs even if you're young and healthy. You're responsible for whatever risks you're willing to take, but in this class I will be undercooking eggs, "pooling" eggs, letting eggs sit at room temperature, etc. Do it or don't do it, it's up to you.

Despite the nutrition and safety concerns, though, egg consumption has been slowly rising since its '90s low. In 1975 Americans ate an annual average of 277 eggs per capita. The all-time low was 233 in 1995. As of 2002, consumption had rebounded to 252. These days, however, nearly a third of the average American's egg intake comes not from whole eggs purchased in the market but from eggs incorporated into prepared food products. In 1975, of those 277 eggs, only 30 were consumed in processed form. Today, 74 of those 252 aren't whole eggs. Thus we are still seeing a decline in the kind of egg consumption that is important from the standpoint of cuisine and cooking.

Weights and Measures

For the bulk of this discussion, I'll be assuming the American standards for eggs that have been set by the USDA. Those of you in other countries may need to do some conversion, but you'll find that local regulations in most nations roughly correspond to one another. These links will take you to: the EC regulations, the Canadian regulations, and the Australian regulations.

Eggs in the US are categorized in size ranges from Jumbo down to Peewee. Most published recipes assume Large eggs. These designations are not made on a per-egg basis, though -- they are averages based on cases of cartons of 12 eggs, with various tolerances allowed as per lengthy and obscure regulations. Any given egg from a carton could range in weight by quite a bit -- so much so that in applications where precision is important, such as professional baking, you will always see eggs measured by weight rather than by number of eggs.

The following are the USDA's guidelines for what a carton of eggs should weigh, followed by a calculation of the weight of an individual egg.

Jumbo

Carton weight: 30oz.

Egg weight: 2.5oz.

Extra large

Carton weight: 27oz.

Egg weight: 2.25oz.

Large

Carton weight: 24oz.

Egg weight: 2oz.

Medium

Carton weight: 21oz.

Egg weight: 1.75oz.

Small

Carton weight: 18oz.

Egg weight: 1.5oz.

Peewee

Carton weight: 15oz.

Egg weight: 1.25oz.

Remember, though, there are several reasons you can't just use the above assumptions when cooking. First of all, these are weight not volume measures. Secondly, these weights are for whole eggs in the shell. The shell may not weigh all that much, but most people when cracking eggs leave around 1/4oz. of product behind in the shell. If you're cooking a recipe with a lot of eggs in it, this really adds up. (If you want to avoid some of this waste, stick your finger inside the halves of each shell to get out those last bits of white.) And third, of course, because eggs are weighed in bulk there's no guarantee that a given Large egg won't be a bit heavier or lighter than 2oz. In all, you most likely will never be able to fill an 8oz. measuring cup with 4 large eggs -- chances are you will need 5, although this might take you a bit over.

The composition of an egg, from the USDA

Grade and Quality

There is no nutritional or safety-related difference among the various grades of eggs on sale at the supermarket. The grades are complex and the standards go on for pages and pages, but they mostly pertain to the cosmetic and performance characteristics of eggs. The top USDA grade is AA; it indicates a near-flawless shell with a tight internal structure. There is very little difference between AA and A eggs, but the A eggs are allowed to have more imperfections and a looser structure. B eggs are still totally fine, but they tend to have some visible defects and they spread out more -- thus they are not as effective for poaching, frying, and boiling in shell as the AA and A eggs.

USDA illustration of the coherence of various grades of eggs

The grade of an egg, however, has little to do with its flavor. Eggs of the top grade can range from the more flavorful farm-fresh variety (which most people these days have never even tasted) to the less interesting mass-produced supermarket eggs. There is a bit of good news here, though: in researching this class, and in past tastings, I found that if you can find a high-turnover source of supermarket eggs (such as the Fairway market in New York City) you can get pretty good, pretty fresh eggs. They certainly won't be as deeply flavorful as the Greenmarket eggs that cost several times as much, but the primary differences I noticed had to do with appearance and concentration-of-flavor. If, however, your supermarket isn't getting particularly fresh eggs and isn't moving them quickly, they will have off flavors -- you may never have noticed these flavors, but if you do a side-by-side tasting with better eggs you'll pick up on them immediately. This past weekend, the Perlows and I tasted the regular eggs from ShopRite in Englewood, New Jersey, along with two higher-end brands that were about twice as expensive. We agreed that the more expensive, organic/vegetarian/free-range eggs had slightly better flavor when served sunny-side up (just about the purest expression of the egg), but we also agreed that the difference was not dramatic and that the basic eggs from ShopRite were quite good. Also, when buying fancy eggs at the supermarket, pay careful attention to the expiration date. These brands tend to have lower turnover.

Three brands of eggs we bought at the local market; the more upscale brands had slightly deeper flavor but the supermarket brand was probably fresher and as you can see (on the right) had a technically better structure

I think we are particularly prone to be fooled by the color of eggs. The last time I was in the UK I was so impressed by the deep orange eggs sometimes available there that I bought half a dozen of the most expensive eggs at Harrod's (there was even a little booklet of photographs hanging by the display, showing the wonderful treatment the hens received on the organic farm) and snuck them back into the US. But when I compared them to my local eggs, it turned out that the color difference was far more noticeable than any flavor difference. They were a bit better tasting than Fairway's eggs, but no better than my local free-range brands. They sure did look pretty, though.

The Composition of The Egg

As the final part of this overview, I want to make sure we're all on the same page regarding the parts of the egg.

The structure of an egg, from the American Egg Board

The shell is of course the outer layer of the egg. It can be brown or white, or in some cases pastel colors. The color of the shell makes no difference at all to the flavor of the egg -- it's purely an issue of pigmentation. However, you will notice when peeling brown-shelled hard-cooked eggs that it's a lot easier to see bits of shell that you might have missed.

Directly inside the shell are two shell membranes, and inner and an outer. They provide protection against bacteria (the shell itself is quite permeable). At first, there is no space between these membranes, but as an egg cools and loses moisture an air pocket forms in this space. The air pocket is the chief culprit in cracked eggs during boiling -- when the egg gets heated, the air pocket expands and can crack the shell. This can be addressed by pricking the egg with a needle at the large end before boiling.

Next are two layers of albumen, aka the egg white, which are well illustrated in the egg-grading diagram we looked at earlier.

There are a couple of things attached to the yolk that sometimes alarm people, chief among them the chalazae. These are not baby chickens. Don't worry. The eggs you buy in the store are not fertilized -- they're not chickens in any stage of development; they're just the food that baby chicks would have eaten had the eggs been fertilized. The chalazae are simple strands of albumen that hold the yolk in place.

Thanks for joining in the class, and I'll see you back here on Friday for the egg FAQ. We'll start the Q&A sessions next week, when we get to the actual cooking part of the class. In the meantime, if you have a general egg question you'd like to see answered in the FAQ -- a general one such as "How many eggs a year does a chicken lay?" as opposed to a specific cookery question -- please send me an e-mail sshaw@egullet.com and I'll try to include your question on Friday.

Edited July 1, 2023 by Smithy
Restore photos, thanks to Wayback Machine Internet Archive (log)