Ahhhh, the ever versatile, yet humble egg. Although I know there are many people who voluntarily don’t use eggs in their cooking, I’ll confess that’s never been a position I could defend. Eggs are a nutritious, cheap source of protein and one of the few foods that naturally contain Vitamin D, as well as other fat-soluble vitamins such as A, E and K. Eggs are also used as a binding agent, an emulsifier, a thickening agent, and for leavening. In my mind, they are an indispensable part of cooking chemistry.
Let’s get this one out of the way right off the bat. Brown eggs are no more or less nutritious than white shelled eggs. The colour of the shell depends on the type of chicken that laid it. Some chicken breeds, like those who have red ear lobes, are white egg layers. Others, like those with dark earlobes, produce brown shelled eggs. Inside, it’s the same stuff, except…
The colour of the yolk depends on the hen’s diet. Very bright, bold egg yolks indicate a diet that was full of greens.
The egg white is fat free and is about 90 percent water and 10 percent protein When an egg white is whipped, a process technically known as aeration, air is forced into the liquid, creating a foam. Egg whites, properly whipped, will yield about eight times their original volume.This foam traps air bubbles, resulting in a froth that increases height and provides a rising action in a lot of baking. As the foam is baked, the air expands, lifting and providing a lightness to the texture. As the protein continues to heat and congeals, the air is trapped and the shape is retained. This is what gives a souffle or the meringue on a lemon pie its lift and height.
To maximize the volume of your beaten egg whites, you must first ensure that the bowl and beaters/whisk are absolutely grease and oil free. Even a little bit of yolk in the egg whites will cause a problem. That’s why when you’re separating eggs, to do each egg one at a time over a separate bowl and pour the newly separated white into the work bowl. That way, if a yolk breaks and messes up one white, you haven’t lost the entire bowl you had cracked for that angel food cake.
Also egg whites whip up best when they are at room temperature. Eggs separate best when they’re cold. So if you can, leave yourself enough time to separate the eggs and still let the egg whites come to room temperature.
Every one knows that oil and water don’t mix — that is, until you add an egg yolk. The yolk contains lecithin, a fat that can be used to emulsify these two strangers into a smooth mixture. Egg yolk is what keeps mayonnaise or Hollandaise sauce stable.
An egg is often used in recipes to take advantage of its binding ability. In hamburgers, meatballs or meatloaf, the egg proteins tighten up during the cooking process and help keep everything together. Generally speaking, one large egg per pound of meat is the ratio used.
Egg is also used to keep breading adhered to the underlying food. The basic process for breading anything is to roll the food in plain flour, then dip it into an beaten egg mixture, followed by rolling it into the bread crumb coating. If you can, setting the food aside on a wire rack for 10-15 minutes to let the coating dry really helps keep things where you wanted it.
An egg’s ability to hold 4 times its weight in water makes it a good thickening agent in sauces, puddings and custards. Make sure you cook the mixture gently. Since the yolk and the white gel at different temperatures, you need to stir frequently and softly so the egg incorporates into the entire dish, rather than ending up with scrambled eggs in your custard.
Additionally, you don’t want to add eggs directly to a hot dish. Pour a bit of your hot liquid into the lightly beaten eggs and mix vigourously to warm the eggs up. This is called tempering. If cold eggs hit the hot liquid, they will solidify too quickly, leaving you with a stringy mess that no amount of beating will smooth out again. .
In many European locales, and I’m sure other places in the world, eggs are stored at room temperature. They are kept in baskets and they do perfectly well. This would be my preference but, alas, I do not live in an egg-sensible market.
In North America, freshly laid eggs are washed at the hatchery, removing the protective, anti-bacterial coating that Mother Nature provided. In addition to this, eggs are stored under refrigerated conditions before they get to the grocery store. Once refrigerated, eggs need to stay refrigerated for food safety reasons.
Where in the fridge should they be stored? Definitely, not on the door although many fridge manufacturers have an egg shelf on the fridge door. This is the warmest part of the fridge and has the most temperature fluctuations. Generally speaking, eggs should be refrigerated in their carton. Egg shells are porous and can absorb strong smells into the egg, giving them an “off” flavour. That said, I store mine in a large glass vase because I have a very small fridge and need the room.
If you need room temperature eggs, something often called for in baking, you can quickly warm them up by setting them in a bowl of warm (not hot) water for a few minutes.
The best way to crack the egg shell is to smack it on the counter or another flat surface. Cracking it on the side of a bowl or fry pan increases the chances of having egg shell drop into the dish. The force from the thinner edge of the bowl pushes the shell towards the centre of the egg, meaning it’s now in your cake batter.
So what to do when in spite of your best efforts, there’s now a little bit of egg shell sitting in your bowl? The two best methods for removing is to wet you finger and just fish the sucker out. The second method (and probably the most efficient) is to use the larger egg shell to fish it out. The sharp edge of the egg shell will cut through the viscosity of the egg white and help you fetch it.
And don’t forget your eggshells are compostable. They will break down nicely in your regular garden compost. Finely ground egg shells can replace pumice stone supplementation if vermiculture (worm) composting is your thing. You can even add the finely ground shells as a top dressing to your house plants for that extra boost of calcium plants need when they’re growing. (Calcium is used in cell wall structure).
Yes, you can unboil an egg. The white of a boiled egg becomes solid because the proteins get tangled up during the cooking process. Scientists have discovered the way to make it liquid again Why on earth would anyone want to. Well, SCIENCE… On a more serious note, the technology is being pursued because it gives them an insight on how to untangle other proteins, something that might be useful in the medicine of the future.
And that’s it for today. Thanks for reading. Keep cooking and we’ll talk later. More on eggs coming in future columns because I don’t think we’ve fully “egg-splored” this versatile kitchen ingredient.