Why does oil result in a more tender but less fl aky pie crust than plastic shortening? Why might oil result in a less tender cake than shortening? Besides being more tender, what else is different...

Why does oil result in a more tender but less fl aky pie crust than plastic shortening? Why might oil result in a less tender cake than shortening?

Besides being more tender, what else is different about a cake made with high-ratio liquid shortening from one made with other fats, such as an AP shortening?