Oil Instead of Butter for Baking.

Our answer

In some cases it may be possible to switch between oil and butter in a cake recipe but it is not something we recommend. Butter adds a surprising amount of flavour to cakes, particularly vanilla or plain cakes. If oil were used instead the cake would taste bland and be much less appealing. Also if the cake is made by the creaming method - beating butter and sugar together and then beating in eggs - then oil is not a suitable substitute as it cannot be beaten to incorporate air and if oil is used the cake will be flatter and denser than the creamed version.

Unsalted butter also contains roughly 80% fat, 18% water and 2% milk solids so even in cake recipes where the butter is melted you can't switch vegetable oil directly for butter as oil is 100% fat and the cake could become too greasy or heavy. You will need to use 80% of the weight of butter as oil and make up the difference with another liquid such as milk or sour cream.