Hi class, welcome back to baking school. We are currently on lesson 10 of the
baking fundamentals course and today we are talking all about the function of
eggs in baking. Now as you know eggs are an essential ingredient in traditional
baking and they are actually used in three different forms. So sometimes we
use the entire egg in our baked good, sometimes just the egg yolk, and
sometimes the egg white and each of these forms has different functions so
let's dive into each. Okay so let's talk about the anatomy of an egg. When you
crack an egg open you'll notice a few different parts, you'll notice that the
outer part of the egg which is the egg white is pretty clear in color and this
contains mostly water and some protein. Now the middle of the egg has the egg
yolk in it and that is pretty deep yellow in color and this is mostly fat
along with some water and also some protein. Now you'll also notice some
little white strands those are called the kalasa
and that is actually just holding the egg yolk in the middle of the egg. Now
for most baking purposes this is completely fine to leave in but some
bakers do prefer to remove it for things like custard because it just ensures
that you'll have a really smooth texture. The best way to crack an egg is on a
flat surface like your countertop which will give you a nice clean break. You
never want to crack your egg on the edge of a bowl which is going to push shards
of the eggshell right up into the egg.
Okay so let's talk about egg sizing. Now most standard baking recipes are going
to call for large eggs but you will notice that there are other sizes sold
in your grocery store and if you do buy farm-fresh eggs
likely your carton is going to vary in sizes. Now if you're just using one or
two eggs in a recipe, using a medium egg in place of a large egg is probably not
going to make that much of a difference but this does start to matter more when
your recipe does call for a large amount of eggs. You can see here when we've
cracked a medium egg, a large egg, and an extra-large egg
they do vary in volume somewhat. So if there is a large number of eggs in your
recipe this does start to matter more. So I've actually included a chart on the
written part of this lesson for you to see what the conversions are for
substituting eggs in recipes that do call for a large amount. Now I should
also note that when recipes do include the weight measurement for eggs that is
usually a pretty good indicator that it does matter for the egg measurements to
be accurate so I would definitely suggest weighing your eggs when a recipe
does call for it. So as we think about the function of a whole egg and baking
it helps to think about all of the things that make up an egg. So an egg is
made up of a lot of water along with some fat and protein. Now the protein is
going to begin coagulating as it heats up and this adds a lot of strength and
structure to our baked good. Now the fat is going to add moisture and richness
and some flavor and the water is going to contribute to a lot of leavening. Now
if you remember from our lesson on leavening, steam is a great source of
leavening and as the water evaporates off it's going to turn into steam which
is going to lift and rise our baked goods. Now I'm actually going to show you
this video of a Dutch baby rising in the oven one more time. And this batter
contains a lot of eggs and no other leavening agents so everything that is
making this Dutch baby rise is just the water evaporating off the eggs. So when
you think about egg whites on their own in baking they are usually called for
when you are going to whip them into an egg white foam. Now egg whites have the
unique ability to hold a large amount of air after they are whipped. They can
actually be whipped to eight times their size. So an egg white foam is used really
frequently to leaven cakes. It's also the thing that makes souffles rise and then
egg white foam can actually be used all on its own as meringue. So egg yolks are
part of the egg that contain all of the fat so they are used in baking to add a
lot of flavor, richness, and moisture. Now egg yolks are also an excellent
emulsifiers they really help to bind and thicken. Egg yolks are really key
component in custards like pastry cream and you'll see as you heat up a pastry
cream it really begins to thicken and this is because the egg yolks are
gelling as they are heated which really helps thicken up the mixture. Now I
should also mention that egg yolks are really going to prevent egg whites from
whipping to an egg foam so you really need to be careful when separating the
two. The best way to separate an egg is to use your clean hands. Crack your egg
into a bowl and then pick it up allowing the white to drop back down into the
bowl leaving the yolk in your hand. Place the yolk into one bowl and the whites
into a separate bowl. The reason I suggest using three bowls for this
process is so that if you do happen to break a yolk while you are separating
them you are not risking contaminating your bowls of already separated egg
whites. Now as a general rule of thumb, eggs should be at room temperature for baking. They're just more readily absorbed into batters
and doughs when they are at room temperature and egg whites beat up to
their highest volume when they are at room temperature. So now that you
understand all about how eggs work in baking I want to give you your homework
assignment. I'd love for you to try your hand at making a chiffon cake and the
reason I chose this cake is because you are going to use the entire egg in the
recipe but the egg yolks and the egg whites are going to get separated out
during the mixing process. The egg whites will be whipped into an egg white
meringue and then that is going to get folded into the cake batter that does
include the egg yolks. So it's really the best of both worlds you get all of the
richness and flavor from the egg yolks but you're also going to get all of that
lightness from the egg white meringue. Now you can share this in a few
different ways, you can share it in our private base
groupware we always continue the conversation after the lessons. You can
also share it on any of your social media using the hashtag #BBbakingschool
or you can email it to me directly at Bettie@BakerBettie.com. I'll see you
guys next time. Bye!