The reason why a traditional pastry crust is not typically used when making cheesecakes is primarily due to the different textures and flavors that complement each other.
Cheesecake is a dense and creamy dessert made primarily from cream cheese, sugar, eggs, and flavorings. It sets as it bakes and has a smooth, creamy texture. The filling is usually rich and indulgent, and it needs a stable base that won't become soggy when in contact with the filling.
Pastry crusts, such as those used in pies and tarts, are typically made from flour, fat (like butter or shortening), and water. They are designed to be flaky and tender, which contrasts with the dense and creamy nature of cheesecake. When you place a pastry crust under the cheesecake filling and bake it, the moisture from the filling can cause the crust to become soggy, losing its desirable texture.
Instead of a pastry crust, cheesecakes often use a crumb crust made from crushed cookies or graham crackers mixed with butter. These crumb crusts offer a stable base that holds up well to the creamy filling without becoming overly soft. The combination of the crunchy crust and the smooth filling creates a pleasing contrast in texture and flavor, enhancing the overall cheesecake experience.
So, while pastry crusts are perfect for pies and tarts, cheesecakes are better paired with crumb crusts to ensure the best possible texture and taste.