Why must the margarine be rubbed into flour quickly?

You're likely thinking about making pastry! Rubbing margarine into flour quickly is a key step in making flaky pastry, like puff pastry or shortcrust. Here's why:

* Preventing Gluten Development: When you work with flour, gluten develops. Gluten is a protein that forms a strong, elastic network, which is great for bread but not for pastry. Rubbing quickly helps to keep the gluten development to a minimum, resulting in a tender, flaky texture.

* Creating Layers: The goal of pastry is to create thin layers of dough separated by fat. Rubbing the margarine into the flour creates small, evenly distributed pieces of fat, which later, during baking, will melt and create those airy layers.

* Maintaining a Cool Temperature: The margarine should be cold when you rub it in, and keeping the mixture cold is important. Warm margarine will melt too much and prevent the flaky layers from forming. Rubbing quickly helps keep the temperature low and prevents the margarine from becoming too soft.

Tips for Rubbing in Margarine Quickly:

* Use Cold Ingredients: Make sure both your flour and margarine are chilled before you start.

* Use a Rubbing Technique: Use your fingertips or a pastry blender to rub the margarine into the flour. Don't overwork it!

* Work Quickly: Be efficient and don't let the dough become too warm.

* Stop When Pea-Sized Pieces Form: When the margarine is evenly distributed and the mixture resembles breadcrumbs, you're ready to proceed.

Let me know if you have more pastry questions!