Baking 101: Function of fat in baking
Types of fat. If you thought fats only came from meat or seemingly nowhere when you’re trying to dispel it from your middle then you and I need to have a chat. Fats are an essential element in baking giving you texture, flavour and colour all in one. Fats come in all shapes and sizes when it comes to baking and it can be difficult to know what’s best for your bake.
In baking gluten is essential, but often we don’t need quite as much gluten as the flour will provide. Fats coat the gluten molecules so they cannot combine into long chains. This is what makes your cake soft and tender not chewy like a bread. It contributes to the fluffiness of your cakes by the air pockets that form when fat is creamed with sugar. Fat also provides flavour and soft mouth-feel.
So, you can see that fat is not an ingredient to fear and that it is actually integral to the baking process. Let’s start out with the different qualities of fat and their functions in baking. This will give us a base when looking at the different types of fat.
Fats are hydrophobic
Put simply fats repel water. This shouldn’t come as a surprize if you’ve ever tried to make an oil and vinegar dip for bread, the vinegar will stay in a nice little bubble in the centre of the oil. An emulsifier is needed to combine the two. Like when making mayonnaise we rely on an emulsifier to hold the suspension together. This quality is especially crucial in baking as when the fat coats the gluten molecules no liquid can get to the gluten. If you haven’t checked out my post on flour you should check that out as we go through the formation of gluten.
Fats provide richness and flavour
If you’ve ever tasted a pie crust made with all vegetable shortening vs all butter you will know the difference straight away. Different fats taste different and give your bakes a different flavour. The most flavourful fats are butter, lard and olive oil and because of this flavour you have to be careful with which you choose for your bake. Lard for example is great in a savour pie crust but would leave a bad taste in your mouth in a cake.
As discussed earlier fat coats protein in flour preventing water coating the proteins and slowing down gluten development. Fat also works to shorten gluten strands. This is why a cinnamon roll and a baguette have different textures. They are both a bread product made with flour and yeast but the cinnamon roll is made with fat whereas the baguette is made without.
Like sugar, fat is essential to the rising of cakes. When beaten with sugar air pockets form, supported by the fat. Butter is used in cakes because it also contains water which evaporates when baked, this rising steam creates lift in your cakes. This is more visible when baking puff pastry, layers of butter are folded in-between layers of pastry, when baked this butter melts and evaporates lifting the pastry and creating air pockets. This is what creates the distinctive flakes.
Types of Fat
Types of fat – solid fats
Fat traditionally comes in 2 types, liquid and solid. Solid fats can be melted but generally re-solidify in cooler temperatures. This gives solid fats a different function in baking than liquid fats.
Traditionally the three maid solid fats used in baking are butter, lard and vegetable shortening. However, in recent years coconut oil has gained popularity
Shortening is made from 100% vegetable fat and is solid at room temperature. Shortening gives pastry its wonderful flakiness and gives cookies a lighter feel. It also gives bread stability and a nice smooth texture. It is generally advised to use shortening in conjunction with butter because shortening gives your bake no flavour or colour at all.
Butter consists of 80% fat and 20% water combined with milk solids. This water content works wonderfully in cakes as the water evaporates helping the cake to rise. As discussed, it is also helpful with pastry as the water evaporates creating air pockets giving your pastry that distinct flakiness. Butter also imparts flavour into your bakes.
Clarified butter is butter that has been heated to remove the sediment of milk solids therefore turning a clear colour. It is 100% fat. This means that it can be used as a substitute for any other 100% fat but not butter in baking. It has a rich flavour and beautiful golden colour.
Margarine is made from vegetable fat but unlike shortening contains only 80% fat. This means that it can be used instead of butter however it lacks the flavour of butter. If you are trying to cut calorie content, I would recommend using both butter and margarine.
Coconut oil, whilst technically a solid at room temperature, coconut oil has a lower melting point than butter. Since it is 100% fat contrary to popular belief, I don’t think it can be substituted for butter in most cases. It simply lacks the water content; this water needs to evaporate to aerate cakes and pastry. Substituting butter for coconut oil produces denser cakes.
Lard is traditionally made from pig or cow fat. It can be used in any recipe that calls for vegetable shortening however you need to keep in mind the strong meat flavour. This makes in perfect for use in savoury pastry.
Types of fat – Liquid Fats
Liquid fats do a different job in baking. Since they cannot be creamed with sugar to aerate and don’t contain water to evaporate, we need to think about them differently. Oil does provide fantastic moisture to cakes that are denser and don’t need as much lift. Brownies and carrot cake for example use other raising agents to provide the little lift desired. The desired end product is very moist and oil provides that.
Vegetable oils are generally flavourless oils which can be used interchangeably. You may also use sunflower oil.
Olive oil is fat obtained from grinding whole olives and extracting the juice. Used in focaccia bread and other Mediterranean savoury bakes. Its strong flavour means it lends itself to savoury bakes and should be used carefully as the flavour can overpower your bake. Can be substituted for vegetable oil.
Other nut oils are mostly used to flavour baked not as a primary baking fat.
Cocoa butter is a pale yellow, pure, edible vegetable fat extracted from cocoa beans. Used in chocolate chips.
Ghee is a type of clarified butter with a subtle yellow colour and rich nutty flavour, used as a substitute for butter in many cultures. Vegetable ghee, made from various vegetable oils, is more commonly used than ghee made from butter.
So there you have it my types of fat and how they are used in baking. Let me know in the comments if you find this type of post helpful and if there are any other topics you want me to cover.