Succulent Science: The Role of Fats in Making a Perfect Pastry
Have you ever wanted to bake the perfect pie to help warm up the cold holiday season? No matter whether it is apple, pumpkin, chocolate, pecan or pumpkin pie, every good pie needs a well-made pie crust. If the pastry crust is heavy or chewy then that can really affect how much you enjoy the pie. But how do you make a pastry crust that is light and flaky? In this scrumptious science activity, you will find out by investigating how the temperature of fat used (in dough) can affect a pastry’s texture and taste, all while baking your very own pastry crusts!
This activity is not appropriate for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.
Going to a bakery can be fun adventure – there is usually a display of delicious sweets and pastries to tempt the palate and the eyes. Many of these treats are made using wheat flour. Wheat flour is an interesting substance. When you mix water with other powdery substances, you just get a paste. But when you mix water with wheat flour, you get a very different material, one that is the base for so many tasty foods, such as breads, pastas and pastries, including pie crusts. Pie crusts (also called pastry shells) were first developed in the Middle Ages to contain and preserve meat preparations, resulting in dishes like the Cornish pasty.
The taste and texture of a pastry depends upon the makeup of its dough, which typically contains water, flour and fat. Gluten proteins in flour allow the dough to be plastic (it can change its shape) and elastic (it bounces back and returns to its original shape), and turn into a fluffy baked good. The fat in the dough, on the other hand, helps give the final product its texture and flavor. Get ready to make homemade pastry crusts to find out how differently prepared fats affect them!
Extra: Repeat this activity but skip the step where you chill the dough in the refrigerator. Is chilling the dough required to make a good pastry shell?
Extra: Try this recipe using lard and/or vegetable shortening instead of butter. Does using one of these other ingredients make a good pastry shell? How do pastry shells made with these different types of fats compare?
Extra: If you have access to a microscope, you could do a closer inspection of the pie crusts. How do the pie crusts compare to each other when viewing them through a microscope?
Observations and Results
Did you and your volunteers find the pastry shell made using refrigerated butter to be bumpier, less tender and flakier than the pastry shell made using melted butter?
When mixing the butter into the pastry shell dough, you probably found it much harder to mix in the cold butter (which was sold and difficult to break into pieces) than to mix in the melted butter (which was a liquid and so should have easily blended together with the flour, salt and ice water). When rolling out the chilled disk of dough, you should have similarly found it much easier to roll out the dough with the melted butter than the dough made with the cold butter. Overall, the melted butter should have more easily coated and separated the flour particles from each other, which resulted in a smoother pastry shell when using the melted butter compared to the cold butter. You and your volunteers may have also generally found the pastry shell made using melted butter to be less flaky and more tender than the pastry shell made using cold butter, although some people may differ in their opinions.
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Teisha Rowland, PhD, Science Buddies
Science Buddies |
Baking, pastries, fats
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