Dairy

Ingredients

• Buying & Storing Eggs
• Varieties of Egg
• Cooking Eggs
  • Poaching
  • French Omelets
  • Boiling Eggs
• Nutrition & Health

Buying & Storing Eggs

• Buy eggs only from a source where you can be confident the storage temperature has been maintained at 45°F/7.2°C or below from farm to you. Eggs must be transported in refrigerated trucks.
• Buy eggs from a source with good turnover so they will be as fresh as possible.
• Storage: Raw eggs will keep in the refrigerator for 4 to 5 weeks but will lose moisture increasing the size of the air pocket. Old eggs will float high when boiled.
• USDA Graded eggs must have a date indicating when they were washed and packed. This is a three digit date starting at 001 on 1 Jan and incrementing to 31 Dec. "Sell by" dates are not required but if there is one it must be no more than 45 days from the "packed" date.
• Refrigerate eggs immediately at 40°F/4.4°C or lower. They should never be unrefrigerated for more than 2 hours.
• European Eggs:   In Europe eggs are sold unwashed and are stored at room temperature protected by the waxy coating the chicken applies. American eggs are washed, sanitized and coated with mineral oil to replace the waxy coating. After washing they must be refrigerated until used.
• Fertile Eggs have no detectable nutritional benefit over standard sterile eggs but they are sold at higher prices as "health food".
• Organic Eggs that are carefully produced and handled just plain have to be better for you than industrial eggs, particularly for young children.
• Brown or White?   There is no detectable difference. Yolk color varies depending on the hen's diet.
• Blood Specs on the yolk are not a problem and indicate freshness - they fade with time.
• Hazy Whites are not a problem and indicate freshness. Whites become clearer with age as carbon dioxide is lost through the shell.
• Storage: Hard boiled eggs can be kept refrigerated for no more than 7 days.
• Araucuna chickens from South America lay light green or light blue. Anything the least bit different (and more expensive) gets promoted as "health food" these days, but claims these eggs are lower in cholesterol have not been confirmed.

Varieties of Egg

Chicken Eggs - [Gallus gallus]
American chickens lay about 66 billion eggs per year in commercial production (yes, that's a "b"). In the U.S. the word "egg" without a qualifier means a chicken egg and if a size is not given presume "Medium" or "Large". Baking recipes in particular should be specific about size.

Freshness:   For poached eggs and omelets you want the freshest eggs you can lay your hands on and grade AA is best. If you'll be hard boiling and peeling your eggs buy them a week in advance and store them in the fridge. This will make peeling easier. Other applications aren't so sensitive. As eggs are kept in storage they will not only lose weight, they will also drop from AA to A and then B and even lower.

Grades & Sizes:

	AA:	Thick firm whites and a round yolk, clean, no cracks or stains. Note: Jumbo eggs are never AA for technical reasons but Extra Large can be.
	A:	Reasonably firm whites, otherwise same as AA. Jumbo eggs should be grade A.
	B:	Thinner whites and wider yolks, no cracks but may have slight staining. These are sold mostly to food processors.

Duck Eggs
Responding to demand from a rapidly expanding Asian population, duck eggs are becoming quite common in North America. Naturally California is a leading producer because hundreds of Asian markets are close at hand. California duck eggs are considerably larger than those we see imported from Asia, running around 3-5/8 ounces, 2 inches diameter and 2.9 inches long vs. about 2-5/8 ounces. The jumbo chicken egg on the right weighs 2-1/2 ounces.

When buying them be careful, fresh and salted duck eggs look exactly the same so check the sign and label so you get the kind you want. California salted duck eggs are not dyed red.

Duck eggs hard boil just fine using the same instructions as for chicken eggs (see links above). The shells are much stronger and you should chill them thoroughly all the way through before attempting to peel them. The yolks are a bit richer but they are otherwise interchangeable with chicken eggs, weight for weight.

Quail Eggs
High demand for quail eggs began in North America with the spread of Japanese sushi bars (uni with a raw quail egg broken over it made as gunkan nigiri sushi is one of my favorites), but they are also appreciated by other Asian communities. The photo specimens averaged 0.47 ounce, 1.47 inches long and 1.1 inches diameter.

The specked quail eggs found in markets are generally from a Japanese quail variety now widely raised for egg production - the photo specimens came from Ontario California. Some quail native to North America and Europe lay white eggs but they are raised mainly for eating.

Quail eggs are generally found in the egg section of Asian markets packed in tiny plastic egg cartons holding 10 eggs, but sometimes as many as 18. In the sushi bars quail eggs are most often used raw, but other Asian peoples use them cooked. In Thailand they are fried sunny side up and sold by street vendors 6 or 7 to a bowl. Jars of pickled quail eggs for Vietnam are quite common now. These eggs are also a local specialty in parts of North America, either hard boiled as garnishes or pickled.

Goose Eggs
While many geese are raised in North America, you're not likely to find goose eggs in your local markets unless you live next door to a goose farm. They are considerably larger than duck eggs, pointier than most eggs and may be white or colored.

Ostrich & Emu Eggs - [Struthio camelus / Dromaius novaehollandiae]
The ostrich is native to Africa but is now farmed worldwide. Ostrich eggs are very large, around 6 inches long, weigh around 3 pounds and the shells are exceedingly hard and thick to prevent animals from breaking into them. While ostriches are farmed in North America, their eggs are not commonly available here.

Emus, native to Australia, lay a slightly smaller egg generally colored a greenish black with a shell a little softer and easier to carve than the ostrich egg. Emus aren't farmed as much in North America as the ostrich, though they are friendly and playful. As with ostrich eggs, emu eggs are sold in North America mainly for engraving and crafts rather than for eating.

Rheas (native to South America) and Cassowariess (Australia and New Guinea) are other large birds related to the ostrich but rheas are too dangerous and unfriendly to be popular and cassowaries are listed as endangered.

Turtle Eggs
Sea turtles lay their eggs on land, buried in sand and left to be incubated by the sun. These leathery shelled eggs have been eaten since prehistoric times but are no longer on the menu due to the endangered status of sea turtles. Serious fines and possible imprisonment apply to posession, transportation or consumption of sea turtle eggs. The eggs in the photo were gathered in Brazil as part of a conservation effort.

Preserved Eggs - [1000 year eggs, Century eggs, Hot vit bac thao (Viet)]
Preserved eggs are most commonly duck eggs but chicken eggs and quail eggs can also be used, The duck eggs used are about the size of American extra large chicken eggs at around 2-1/4 ounces each.

Preserved eggs are available in markets serving East and Southeast Asian communities, generally individually wrapped and packed 6 pieces to a styrofoam block. In times long past (1960s) they were shipped packed in rice straw in huge glazed clay pots which, once empty, were sold at high prices in Chinatown art stores.

Eggs were traditionally preserved by coating with an alkaline slurry and allowing them to age for three months to a year. Various mixes of alkaline clay, ashes, quicklime and other materials have been used. Today commercial eggs are made using lye or sodium carbonate mixed with tea, salt and other materials. In China highly toxic lead oxide is sometimes used to speed the process but leaded eggs are not allowed into North America.

The process converts the whites into a stiff gel, transparent and dark amber in color. The yolks are turned blue-green, jelly like on the outside and gooey at the center with a distinct sulphur / ammonia aroma. The shells remain nearly white with a light blue-gray tint.

Many Americans have eaten preserved egg without realizing it - it's the mysterious stiff black gel in the center of flaky buns sold in Chinese bakeries.

Tea Eggs & Soy Eggs
These are popular appetizer eggs made in the home or sold by street vendors in China. Both are considerably more interesting visually than regular hard boiled eggs - and more flavorful. You can easily make them yourself from regular North American chicken eggs (and yours will be lead free). Recipe for Tea Eggs. Recipe for Soy Eggs.

Salted Eggs - [not vit muoi (Viet). itlog na maalat (Filipino)]
These can be either duck eggs or chicken eggs with duck eggs preferred (less breakage, richer flavor). They are made by a similar method as Preserved Eggs, but coated with salt mixed with clay or charcoal rather than alkali. They may also be made by soaking in a saturated salt brine.

Salted eggs are popular in China, the Philippines and Vietnam so can be found in markets serving those ethnic communities. You can make them yourself fairly easily using the saturated brine method. Commercial salted duck eggs are often dyed red or wrapped in red plastic so they won't be mistaken for other types of egg, while salted chicken eggs may be dyed blue or green.

In many recipes only the rich oily yolk is used. Integrity and color of the yolk depends on the exact process. The yolk is popular in China to represent the moon in moon cakes The white is much saltier and has almost no other flavor..

Many are sold already cooked (check the package). To cook, put them in water to cover and bring to a boil. Once the water is boiling turn down the heat and simmer for about 50 minutes. These eggs are often impossible to peel neatly, but that's not really a problem since they're generally chopped up as a flavoring ingredient and the yolks are often crushed as a topping for rice.

Feathered Eggs - [Balut (Filipino), Hot vit long (Viet), Pong tea khon (Cambodia), Maodan (China)]
These are fertile duck eggs incubated for 16 days to develop the embryo. This method of eating eggs originated in China (where else) but is now particularly popular in the Philippines, Vietnam and Cambodia. California, never slow to recognize a market, produces these egg commercially for our rapidly expanding Southeast Asian communities.(E2).

I will spare you the detail pictures, but if you'd like you can find some at Wikipedia. In Asia these are rarely sold uncooked, but in North America they are often sold raw. Use the instructions for Boiling Eggs - Hard for cooking.

These eggs are most often served as appetizers though have recently appeared in other dishes in the Philippines. Serve with a little salt or a chili / vinegar dip - and plenty of beer. Some of you may need to start with the plenty of beer and get to the eggs later.

Nutrition & Health

Nutrition:   Eggs are a high protein food, and their protein mix is so good it is the standard by which other protein sources are judged. They did get a bad reputation from vilification by the American Heart Association claiming their high cholesterol would clog your arteries. That campaign was based on incomplete studies and faulty science and has been largely discredited. For a nutritional breakdown see Note-E8.

Cholesterol:   Some years ago the American Heart Association vilified eggs as being high in artery clogging cholesterol and strongly recommended against eating them (they allowed maybe two a week if you wanted to live dangerously). This caused a decline in egg consumption in North America.

They have had to back off on the shrillness but still recommend against eggs (these people won't even admit they were wrong promoting trans fats). The truth is, nearly all cholesterol is manufactured within the body (it's essential for brain function, etc.) and most people absorb very little from dietary sources.

It has also been shown that for increases in total cholesterol from dietary sources HDL and LDL increase simultaneously, so the net impact on heart disease is statistically negligible.

Salmonella:  

Salmonella bacteria can live and reproduce in a wide variety of animal products but will be reduced to a safe level when heated to 160°F/71°C. A great many recipes using eggs require keeping the temperature well below this level which makes proper egg handling a critical health matter.

It was long thought that uncracked eggs were sterile inside but it has been found that about 1 egg in 10,000 may have been infected by the hen. This doesn't mean it'll make you sick if you gulp the egg down raw, but it does mean proper temperature control must be maintained because this bacteria multiplies rapidly at temperatures above 40°F/4.4°C.

American egg producers have been making great efforts to completely eliminate this problem by eliminating salmonella at the production end. It is interesting to note that the high profile sanitation and screening measures instituted for salmonella are also effective for avian flu, a problem which has not surfaced in North America yet.

Infections from home cooked food have been almost nonexistent - infections have almost always been from institutional sources (restaurants, health care and elderly care establishments). These establishments use "egg pooling" where a number of eggs are mixed together and ladled out of the pool for use. Pooling eggs tremendously magnifies the possibility of infection from outside sources and the possibility of unsafe temperatures.

For institutional use pasteurized egg products are recommended by the USDA and CDC. See Note-1 for alternatives which may be more satisfactory in many instances.

For normal consumers the safe handling rules at the top of this page should be sufficient to prevent illness, but those who feel they must be extra cautious can purchase "pasteurized in the shell" eggs in some areas of the country. These do cost about twice what regular eggs cost.

There have been no studies as to whether small farms and organic growers produce a safer or less safe egg in regard to salmonella than the industrial producers.

Despite all measures in place and being implemented it is still recommended that "undercooked" eggs not be served to infants, pregnant women, frail elderly people or those who have a compromised immune system.

Links

• E1 - Egg Safety - Hospitality Institute Assuring Safety of Egg Yolk-Based Sauces and Salad Dressings
• E2 - Duck eggs, fresh, salted, crunchy - Metzer Farms
• E3 - Ostriches, Emus, Rheas and Cassowary - eggscape.com.
• E4 - Egg Safety - U.S. Department of Agriculture.
(updated March 2007)
• E5 - Salmonella - Medical College of Wisconsin (1999 doesn't reflect recent progress).
• E6 - Cholesterol - The Impact of Egg Limitations on Coronary Heart Disease Risk: Do the Numbers Add Up.
• E7 - Cholesterol - Understanding Cholesterol Dr. Ben Kim.
• E8 - Egg Nutrition - British Egg Information Service.