Final answer:
The best indication of doneness for pies and shells is the color, particularly when the crust turns golden brown, signaling that the pie is fully baked.
Step-by-step explanation:
The best indication of doneness when baking pies and shells is color. While smell, taste, and texture are important elements that contribute to the eating experience, it's the color that typically signals that a pie or shell has been cooked through. When baking, you can observe the crust turning a light brown, which indicates that the dough has transitioned from being flexible to much more rigid. This is similar to watching a pizza bake; when the crust is lightly browned and the cheese is melted, it is generally understood that the pizza is done.
Other observations that can be made, similar to a chemist analyzing a new material, include assessing the state of the food (whether it is a liquid or a solid), its temperature, and texture. In the case of a pie or shell, when the crust is firm and a golden-brown color, it is a strong indication that the pie is fully baked.