What is the function of cornstarch in pastry cream?

Cornstarch plays a crucial role in pastry cream as a thickening and stabilizing agent. When heated, cornstarch absorbs liquid and swells, which helps give the pastry cream its characteristic smooth and creamy texture. As the mixture cooks, the starch granules gelatinize, thickening the cream and allowing it to hold its shape once cooled. This stabilization is essential, especially when the pastry cream is used as a filling for pastries, as it ensures that the cream does not separate or become runny.

While sweetness, flavor, and texture are important components of pastry cream, these functions are not primarily attributed to cornstarch. Instead, sugar provides sweetness, various flavoring agents like vanilla enhance taste, and other ingredients contribute to the overall texture of the pastry cream. However, cornstarch specifically serves the vital function of ensuring the mixture remains stable and can be effectively used in various pastry applications.