Thursday, March 14, 2013

Happy Pi day! / Some quick pie tips

It all comes together pretty well for pi day, it's possibly the only one of the cool irrational numbers that can be broken up nicely into a date (unlike my favorite, phi ~1.61) AND sounds like a tasty, round dessert.  So duhh it's a great time to share some sweet pie tips.

If you like a crisp bottom crust, consider pre-baking the bottom crust, using a dull metal pan.  Black in color I believe would be best, since black materials absorb heat most effectively (allowing more heat to be transferred to the pie via conduction), while a shiny metal pan would reflect heat away.  A glass pan does not have the free electrodes that a metal pan would have, and so heats up slower.  

Diagram of two metal pans in a 400 F oven.  The wavy red lines indcate radiating heat within the oven.  The black metal pan absorbs most of the heat, which can be transferred to the pie via conduction.  The pan on the right reflects most of the heat away, leaving little to transfer to the pie.
Another key factor to consider is the moisture of the pie contents.  If you leave all the fruit liquids in, the pan material almost won't even matter.  You can choose to either cook your pie contents on the stove at low heat to get rid of some excess moisture, or wait 10 minutes or so for moisture to be leached out of the fruit.  The fruit will lose a fair amount of moisture over time just due to the fact that cells are damaged during the cutting process, and due to the presence of relatively high sugar/salt concentrations outside the fruit cells, causing some cells to rupture.  I like to not waste these fruit juices, and will pour them into a pan and heat on the stove until thickened, giving you a nice caramel-like sauce.

Or if you like softer bottom crusts (like me, since I like the variety of texture and that it soaks up that tasty pie juice), you can opt for the glass or shiny metal pans and retain all the extra moisture by NOT pre-cooking your pie contents or discarding liquids given off by the fruit.

Check out my plum pie recipe to the right!  
Can also be adapted for other fruits, like for a crispy crust apple pie.

Some sick crust weaving skills