After researching numerous genoise recipes, I notice that there are some differences among them. Although all recipes were for the same end result, the amount needed for each of the ingredients was never the same.
1. 4 eggs
1/2 sugar
3/4 cup cake flour
7 TB butter
2. 4 eggs
2/3 cup sugar
1 1/2 cups flour
3. 4 eggs
1 cup cake flour
1/2 cup sugar
4.6 Eggs
1 Cup sugar
1 1/3 Flour
There are others but you get the idea.
As baking is supposed to be an exact art, I am curious as to why the recipes would not be more similar. For only one cake, the different amounts would have a greater impact, I would think. I'll be making as many different recipes as I can and taking notes but was wondering if you have any thoughts.
@chefwriter Hope you are having fun at your experiments!
I do find myself having to add to the voices here as a lot of people generally mix up genoise with the Victoria sponge that has butter (an extra fat added)
So in your OP you had asked what is the difference between the recipes posted:
1.) This is a recipe for a Victoria sponge (which often gets lumped in with genoise but is completely different)
2, 3 & 4.) These are genoise recipes
To understand why recipes are the way they are is to understand the science behind each ingredient in a recipe and why they are there.
EGGS: While we can spend a great deal of time studying to understand all of the properties that eggs have we will just stick with the recipes at hand.
Aerator: Eggs have the capacity to trap air through foaming which will have a leavening effect on your baked goods. As this mainly applies to egg whites, egg yolks can be foamed as well to a lesser degree.
They are an integral part of the structure of baked goods as structure happens when the egg proteins coagulate in the batter or dough after coming in contact with heat. As eggs carry a distinctive flavour depending on preparation (i.e.: scrambled egg vs. egg inside brioche). If brioche did not have egg in it, besides its appearance being off, the flavour would be noticeably different. Eggs have a direct effect on binding the ingredients in a batter or dough, which effect not only texture but flavour as well.....it is especially important to have proper emulsion. Eggs add colour not just as an egg wash but in the dough or batter itself which browns while baking (called Maillard browning - it is the caramelization of sugar in the presence of protein). Also....eggs add a nutritional value.
Typical weight of an unshelled egg for most recipes is 50 grams each whole, so for a 4 egg recipe this would be 200 grams or 7 ounces.
FLOUR: The main purpose of flour is to provide the structure or body (along with eggs) in a dough or batter. Gluten (a protein) is mostly responsible for the structure of a dough or batter, but the flour in itself does not contain gluten. It contains gluten and gliadin (both proteins), which together will produce gluten when they come into contact with water and during the mixing process. The longer a dough mixes, the more gluten will develop in a given dough or batter. So while it is desired in certain doughs, like brioche, it is not needed in the above batters. Different varieties of flour have different percentages of protein. It also contributes to flavour and in conjunction with sugar, produces colour through the Maillard browning mentioned above. It also absorbs liquids which helps bind all the ingredients together in a dough or batter as well as adds some nutritional value.
The best type of flour used in these recipes above would be Cake Flour. It has 7 to 8 percent protein and is good for all types of sponge cakes. Pastry flour is 8 to 9 percent protein and is good for muffins. All-purpose flour is 9 to 10.5 percent protein and can be used for all other batters and dough. Bread flour is 11 to 13.5 percent protein and only good for most viennoiserie or lean dough breads. White whole wheat flour is 13 to 14 percent protein and best used in sourdough bread. This gives you an idea as to why we use the proper flour for the proper application (recipe).
SUGAR: Is mainly used to sweeten but has other contributions to baked goods. In yeasted doughs, it promotes or speeds up fermentation, since sugar is the food yeast uses to ferment. It also acts as a tenderizer since, like butter, it interferes but doesn't prevent gluten strand formation by delaying the formation of structure. The more sugar in a batter or dough the more tender it will be. However, too much sugar will over tenderize the dough, making it a spongy, soft mess, as well, if the dough contains yeast it will grow too quickly. Sugar contributes to colour by browning easily in conjunction with the flour proteins (Maillard browning).
In foamed sponge cakes, it will assist in stabilizing the egg foam by slowing down the unfolding of the egg proteins, which will prevent the over whipping of egg foams, especially egg white foam. It also stabilizes the foam because as the sugar comes into contact with the moisture found in eggs, it will dissolve and this liquid sugar will help trap and support air bubbles.
Now....butter and salt, as you can see, added in will produce a different type of outcome and product. Hence not a genoise but a different sponge altogether.
BUTTER: Will provide flakiness, flavour, moisture and volume, and it acts as a tenderizer in baked goods. It 'softens' a baked product by interfering with the structure formation achieved by the flour and eggs. Butter fat will coat the gluten strands, reducing gluten development since glutenin and gliadin will not be able to come into contact with the water (liquid). Remember the water needed for gluten development. So instead of having longer strands of gluten, the dough will have shorter strands which means the product is tenderized.
As all butter is NOT the same, please choose an unsalted creamery or country churned butter that has a very light whiter colour to it than a regular "butter" that is very yellow and has salt in it. I could go into the science of this as well but it would make you really fall asleep reading it all.....lol
SALT: The main function of salt is flavour enhancement. Of course used in dough with yeast it becomes a way to help control and slow down fermentation. Other functions of salt include increased colour of crust and strengthening gluten bonds, which makes dough more uniform.
Get into the habit of weighing every ingredient, have every ingredient at its right temperature before mixing (i.e.: eggs at room temp, etc.) and paying attention to heat temperatures in oven, as this produces the exact outcome every bake.
Please remember....baking is a science not an art so it DOES count as to knowing why you are using and what for. As for the rest....delicious mistakes are sometimes the best inventions and knowing where the mistake was made makes for a new recipe to share!
So that my friends is the science behind the madness that is our baking/pastry world. If you would like more specific info on anything else don't hesitate to ask. /img/vbsmilies/smilies/smile.gif