I wanted to start the 'Baking Basics' series with eggs because they’re kindof a miracle food. Forget your goji berries and your kale people, eggs are where it’s at! Combine eggs with flour and sugar, and you’ve got three of the heavyweights of the dessert world. As in, if you're stuck on a desert (dessert?!) island and you care more about pancakes than hunting for wild game or fashioning a shelter, you'll need these power players.
A wee bit of history...
We don't have proof that goes back far enough, but it's likely that bird eggs have been roasted ever since man discovered fire (and were probably eaten raw before that), and we know from the recipes of ancient Rome and Egypt that sweet custards were mixed up thousands of years ago. By the medieval era, the French were whipping up creme anglaise and egg white foams, and by the time Monsieur Escoffier came along over a hundred years ago (with no fewer than 143 egg recipes in his Guide Culinaire), the road was well-paved for the sauces, foams, meringues, souffles and pastry creams we make today. I sometimes marvel at how much trial and error must have gone into some of these creations. Seriously - I marvel!
....and a pinch of science
Because it is designed to contain everything needed to create and sustain new life, the egg is an ideal human food. It contains a balanced portion of nutrients, all safely contained in a waterproof package, that lasts for weeks with little to no care. Genius!
Eggs are made up of the fatty yolk (vitellus) and near fat-free white (albumen). But before you whip up that egg-white only omlette, know that the yolk - which is approximately 30% of the weight of the egg - provides the protein and most of the nutrients, while the white is mainly protein and water.
Unfortunately, these days mass production generally makes for unhealthy, unhappy hens, and lesser-quality eggs, so I tell my students to pay a little extra and go for free-range, organic eggs whenever possible. Luckily, here in Montreal, the farmers markets often carry a gorgeous variety of chicken, duck (higher in almost every major mineral than chicken eggs), quail and goose eggs, I definitely recommend experimenting with these - sponge cake with goose eggs is fantastic!
Eggs never cease to amaze me. They’re made up, mainly, of protein, fat and water, but the different ways these three components align make for a dizzying array of textures and flavours. Thanks to the protein, eggs are major structure-builders. They provide support for flour-based desserts, they emulsify (bring water and fat together) batters, and form the creamy base of custards, sauces, and ice cream.
The yellow pigments that make the yolk come directly from the plants eaten by the hen, which in turn have captured and transformed the energy of the sun. Think about that next time you order “sunny side up”!
Did you know...
Back in Ireland, we never refrigerate our eggs, and North American visitors are often horrified to see them in the regular, unrefrigerated isle of the supermarket with the baking products. Could it be that our tradition of having big families (there are seven in mine!) means that eggs don’t hang around for long at home, so, is it ok to leave them out?!
Or maybe the poor insulation in many old houses means that the pantry is a few degrees lower than North American “room temperature”. Nope, actually it's more boring than that. In lots of European countries, egg-laying hens are obliged by law to be vaccinated against salmonella, one of the more dangerous bacteria that can cause food poisoning. In north America, it's not obligatory, so keeping them in the fridge is safer, because it prevents any salmonella on the shells from multiplying. In any case, it’s been shown that an egg ages one week for every day that it’s at room temperature - but kept in the refrigerator, eggs will last up to five weeks without too much change to the quality.
Cool finishing fact: Do you know what the difference is between brown and white eggs?
Is it because:
a) They're bleached to make consumers happy?
b) The feed of the hens is different?
c) The heath of the hen affects the colour?
Nope! None of the above! It’s just different species of hen (like a labrador and a pug!) White chickens in general lay white eggs, and brown chickens lay brown ones. Both equally great in a sponge cake!
So, What do they do in desserts?
Eggs can add the following great qualities to your baked goods:
1. Structure – eggs become firm when heated. Eggs that are mixed in your batter, dough or custard will set and provide structure.
2. Leavening- whipped or aerated eggs can act as a leavening agent in cakes and create a light texture. Egg whites particularly, trap air bubbles and will then hold the air and help achieve a light fluffy texture and a good rise. The process of whipping whole eggs or egg whites is sometimes used instead of a raising agent in cakes. The protein and absence of fat is what gives the egg whites the famous ability to foam.
3. Flavour: the fat content in egg yolks enriches the flavour of baked goods.
4. Appearance – eggs can be used to glaze or coat the outside of pastries, crusts, biscuits etc to give a shine when baked.
5. Binder – eggs emulsify fats and liquids and so are used as a binding agent to hold everything together.
In general, using more whites gives a fluffy and light texture, while using more yolks will create a dense and rich flavour. When both white and yolk are used together, they create a rich flavour and light texture.
Reducing eggs in a recipe (or, "uh oh, I don't have enough eggs and I've already started the cake!)
Due to the range of functions the egg performs in baking, recipes without eggs are pretty uncommon and there will be a significant impact on texture, structure and flavour f you leave them out when you shouldn't. It is difficult to find one ingredient that will do everything an egg can do but that doesn't mean we can't try! Sometimes, if a cake or cupcake recipe calls for 4 or more eggs, you can get away with leaving out one egg and adding a splash of milk. In other situations, possible alternatives include:
For binding – use the new miraclefood, Aquafaba (it's the liquid from canned beans!) or mix flaxseed or chia seed and water to form a gel, or try arrowroot or potato flour.
For leavening – add extra baking soda – although beware: this can cause bitterness and extra browning.
For whipped egg whites - whip together apple cider vinegar and milk until it is frothy and fold
For glazing – soy milk
Final Cool Fact!
Egg shells are edible and a good source of calcium and glucosamine, which is good for joints. You can grind them and add to smoothies or your oatmeal!
Now that you're armed with all this new knowledge - go make something with eggs and be amazed at the power of this humble ovoid!