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The Science of Pie 2014: Video Highlights

The Science of Pie 2014: Video Highlights

June 1, 2014

At the Science of Pie, the world’s first scientific bakeoff, the students of the Science & Food undergraduate course presented results from their final projects in poster format and their pies for taste testing. These pies had to be cooked in one hour and were the summation of all that the students had learned from their pie experiments in the class. Throughout the quarter, the students were challenged to perform a scientific investigation of apple pie and vary different features of the pie such as shape, butter size, and moisture.

The contest was judged by Lena Kwak (of Cup4Cup) and Dave Arnold (of Booker and Dax, the Museum of Food and Drink, and the Cooking Issues Podcast) who were our featured speakers for the 2014 Public Lecture Harnessing Creativity. They were joined by Nicole Rucker (Pastry Chef, Gjelina Take Away), Jonathan Gold (Food Critic, LA Times), Dr. Paul Barber (Associate Professor of Ecology and Evolutionary Biology, UCLA), and Dr. Rachelle Crosbie-Watson (Associate Professor of Integrative Biology and Physiology, UCLA).

The judges had wise words for the students.

Lena Kwak described how she judged the pies.

“With each of the projects we saw today, there were a considerable amount of variables not considered, but the saving grace …was when I tasted their pies.”

Nicole Rucker talked about what makes an award wining pie

“Jonathan and I both know that from Judging Pie Contests, … that you can see a good pie from literally across the room.”

Dr. Paul Barber spoke to the balance of science and pie making:

“No matter how much scientific testing you do, there’s still just this underlying art to making a really good pie.”

Check out some our featured pies from the 2014 contest.

Honorable Mention Pie

Alexis Cary & Matthew Copperman (Team On the Road)

Perfectly Unsoggy Apple Pie

Best Scientific Pie

Christina Cheung, Tori Schmitt, and Elliot Cheung (Team Pretty Intense Pie Enthusiasts)

Beer Crust Apple Pie

Best Overall Pie & People’s Choice Pie

Alina Naqvi & Ashley Lipkins-Scott (Team Apple Queens)

Crumbalicious Apple Pie

Check out our written recap here !

See the whole Video!

Beer Crust Apple Pie

The Science of Pie – June 1, 2014
Best Scientific Pie
Christina Cheung, Tori Schmitt, and Elliot Cheung (Team Pretty Intense Pie Enthusiasts)

Adding alcohol to a pie crust is a fairly mainstream way of obtaining a nice flaky shelter for a delicious filling within. Vodka is the go-to spirit for crusts, but other beverages have found their way into the realm of apple pies too. One team at the 2014 Scientific Bake-Off, team P.I.E. (Pretty Intense Pie Enthusiasts), was intrigued by the plethora of alcoholic options available to them for pie crusts, and chose to use their scientific prowess to determine the best choice. Two variables guided their experiment: how do carbonation and alcohol concentration affect the flakiness of a pie crust?

Christina Chung presenting team P.I.E's experiment to the judges (Photo Credits: Patrick Tran)

Christina Chung presenting team P.I.E’s experiment to the judges (Photo Credits: Patrick Tran)

Team P.I.E. began by making six experimental crust doughs, each containing either water, beer, stale beer, diluted vodka, regular vodka, and Perrier. To measure flakiness, a quality difficult to quantify, they compared the average height for each baked pie dough to indicate how much the dough has risen during baking. To account for bubbles, height measurements were taken at the center and edges of the crust.

Elliot Cheung hard at work preparing pie (Photo Credit: Patrick Tran)

Elliot Cheung hard at work preparing pie (Photo Credit: Patrick Tran)

These pie researchers calculated the elastic modulus of each crust to further quantify flakiness. Elastic modulus of a substance is the ratio of the stress applied to the resulting strain. This ratio can be thought of as a measure of  stiffness, or in our case, flakiness, as the flakiest crust will break the most easily. 

Pie crusts that utilized both forms of beer had a higher average elastic moduli than crusts with other binding agents.

Pie crusts that utilized both forms of beer had a higher average elastic moduli than crusts with other binding agents.

Pie crusts with Perrier as a binding agent yielded the greatest average heights

Pie crusts with Perrier as a binding agent yielded the greatest average heights

They administered force to their crusts by using a pen to mimic the conditions of fork prongs stabbing a pie crust. Measured values of water balanced atop the pen acted as a weight to provide precise values of force.

Through this extensive research, P.I.E. presented data that showed that a pie crust made with Perrier sparkling water created a significantly thicker crust than one made with any of the other experimental liquids. All the other crusts surprisingly rose to very similar heights.  Since P.I.E had observed similar bubble size and bubble concentration in Perrier and beer, they expected that the regular beer crust would yield similar data to the Perrier crust. However, the significant difference between the measured values  of Perrier and beer imply a confounding factor in the experimental comparison. They speculate that Perrier’s high mineral content could alter the vaporization temperature of the liquid, and thus affect the creation of air bubbles and the dough’s infrastructure.

The dedication to detail and the scientific method paid off for these three scientists, as the panel of esteemed judges awarded them the title of “Best Scientific Pie”. As this was a scientific bake off, that is a pretty high honor to hold. Congratulations to the Pretty Intense Pie Enthusiasts, and we thank you for your deliciously scientific dessert!

Christina Cheung, Tori Schmitt, and Elliot Cheung accept their awards for Best Scientific Pie

Christina Cheung, Tori Schmitt, and Elliot Cheung accept their awards for Best Scientific Pie (Photo Credits: Patrick Tran)

Recipe
Beer Crust Apple Pie

(Makes two full pies)

For crust:

  • 5 cups flour
  • 2 TB sugar
  • 2 t salt
  • 4 sticks chilled butter
  • 1/2 to 1 cup cold beer (we used Blue Moon, but any pale ale works here)

Combine flour, sugar, and salt in a large bowl. (if making full recipe will require a very large bowl) Cut chilled butter into cubes and cut into flour mixture with a fork or pastry cutter.  The flakes can vary in texture but absolutely no butter cubes should remain intact. The mixture will resemble corse sand.  Measure out beer starting at 1/2 cup.  Pour in and incorporate into dough. If dough is still dry, incorporate more beer in until the dough is just moist enough to stick together.  Wrap dough in saran and refrigerate for at least 30 minutes, up to overnight.

For Filling and Assembly:

  • 8 large apples (we used a mixture of granny smith and pink lady)
  • 1 cup sugar
  • 6 tablespoons flour
  • salt and cinnamon to taste
  • Lemon zest (roughly 2 TB)
  • one bottle of beer or hard apple cider
  • egg white to brush the top with
  • 1/2-3/4 cup of shredded gruyere cheese

To prep the filling, core and peel all your apples and soak them in enough beer and/or hard cider to cover for 1-2 hours or until the apples are infused to taste. Pour out liquid and reserve for reduction sauce later. Be sure to remove all the liquid from the bowl and allow the apples to dry for roughly 30-45 minutes.  The apples will look significantly less “wet” after the drying period.  After the apples are dry, combine them with flour, sugar, lemon zest, cinnamon, and salt.  Depending on the sweetness of your hard cider/beer, you may need to adjust the amount of sugar used.

Assembly:

Pre-heat home oven to 500 degrees. Section pre-chilled pie dough into four equal segments and roll out two of the pie dough segments. Place these over buttered glass pie dishes and fold into place. Split filling evenly and pour into each dish. Dot top of apples if additional butter if desired (roughly 1 TB per pie).  Roll out the remaining pie crust into two top pieces.  Sprinkle each top pie with an equal amount of cheese.  Cheese amount will depend on strength and personal preference for cheese.  Flour pin well and lightly roll/ press cheese gently into the crust (dough will be very flaky).  Lay top crust evenly over pie with cheese side facing up. Crimp edges and brush with egg whites.

To bake the pie. place and oven and lower temp to 425 degrees F.  Bake at this temp for 25 minutes at which point, rotate the pie and lower temp to 375 for an additional 30-35 minutes. This will produce a pie with softer apples.   Alternatively the pie can be baked at 375 for a full hour, however the apples may remain more al dente.  (Pie was baked in the second way for competition)


Elsbeth SitesAbout the author: Elsbeth Sites is pursuing her B.S. in Biology at UCLA. Her addiction to the Food Network has developed into a love of learning about the science behind food.

Read more by Elsbeth Sites


Crumbalicious Apple Pie

The Science of Pie – June 1, 2014
Best Overall Pie & People’s Choice Pie
Alina Naqvi & Ashley Lipkins-Scott (Team Apple Queens)

This duo of student scientists aimed to create a pie with the crunchiest apple filling by experimenting with four different types of apples: Granny Smith, Red Delicious, Pink Lady, and Fuji. To determine which apples had the greatest resistance to applied forces (and thus remained crunchiest), they measured both the force required to cut through each kind of apple and the “elastic modulus”, which is the amount of deformation caused by a given force.

(A) Team Apple Queens receives the People’s Choice Award at the 2014 Xcience of Pie event. (B) Lipkins-Scott carries the team’s cinnamon crumb pie to the oven. (C) Fuji and Granny Smith apples were used for the Apple Queens’s pie because the team found that these apple varieties had the highest values for elastic modulus. Photos courtesy of Patrick Tran.

To measure the elastic modulus for each apple variety, the team applied a known weight to the apple slice and measured the deformation using a ruler before and after the apples were cooked. (See Panel A & B below). In addition, they wanted to see which apples had the most resistance (and thus, crunch) by measuring the force used to cut through the apples in a “Puncture Force” Test. For this test, the team added increasing volumes of water into a pot balanced over a knife to determine the mass of water required for the knife to cut through the apple slice. (See Panel C below).

After the apples are baked, their lengths (A) and deformations (B) are measured to obtain the elastic modulus. (C) The Puncture Force Test measures the force required to cut through the cooked apples.

Before baking, the Fuji apple had the highest elastic modulus of 170,000 N/m2 and the Pink Lady had the lowest elastic modulus of 130,000 N/m2. After baking, the Granny Smith had the highest elastic modulus of 32,000 N/m2 and the Fuji had the second highest elastic modulus at 28,000 N/m2.

In the Puncture Force Test, the baked Granny Smith apple required the highest puncture force of 18N.

Team Apple Queens found that the cooked Granny Smith apples exhibited the highest elastic modulus and also required the greatest force to cut through. Thus, the Granny Smiths were most resistant to external pressure and remained the crunchiest after baking. Having both the second highest elastic modulus and the second greatest puncture force were the Fuji apples. Based on these results, the team hypothesized that Granny Smith and Fuji apple varieties may contain more of the polysaccharide pectinto fortify their cell walls and make them harder, crunchier apples.

The students of Team Apple Queens stand proudly by their winning pie and poster.

Recipe
Crumbalicious Apple Pie

For the crust:
1 1/3 cup all purpose flour
1⁄2 teaspoon salt
1⁄4 cup (1/2 stick) chilled unsalted butter, cut into 1⁄2-inch cubes
1⁄4 cup frozen solid vegetable shortening, cut into 1⁄2-inch cubes
3 tablespoons (or more) ice water
1⁄2 teaspoon apple cider vinegar

For the filling:
3 Granny Smith apples, peeled, cored, and sliced 1⁄4 inch thick
1 Fuji apple, peeled, cored, and sliced 1⁄4 inch thick
2/3 cup cane sugar
2 tablespoons all purpose flour
2 teaspoons ground cinnamon
2 tablespoons unsalted butter, melted

For the topping:
1 cup all purpose flour
1⁄2 cup cane sugar
1⁄4 cup brown sugar
1 and 1⁄2 teaspoons ground cinnamon
1⁄2 teaspoon salt
6 tablespoons chilled unsalted butter, cut into 1⁄2-inch cubes

Position a rack in the center of the oven and preheat to 375°F.

To prepare the crust:
In a large bowl, mix flour, salt, and sugar. Add butter and shortening; rub in with fingertips until coarse meal forms. We want to incorporate flattened sheets of butter into the flour mixture to get a flaky crust.

In a small bowl, mix three tablespoons of ice water and vinegar. Drizzle the water and vinegar solution over flour mixture. Stir with fork until moist clumps form, adding more water by teaspoonfuls if dough is dry.

Gather dough into ball; flatten into disk. Wrap in plastic and refrigerate for at least 30 minutes. Refrigeration is important for allowing gluten strands to relax (so the dough becomes easier to roll out), and for letting letting liquids incorporate to moisturize the dough.

Roll out dough on lightly floured surface to 12-inch round. (About 1/8th 9-inch-diameter glass pie dish.) Trim overhang to 1/2 inch; turn edge under and crimp decoratively.

Refrigerate while preparing filling and topping.

To prepare the filling:
Mix all ingredients in a large bowl to coat apples.

To prepare the crumble topping:
Blend all ingredients until mixture resembles wet sand.

To assemble the pie:
Toss the filling to redistribute juices and then transfer to crust, mounding in center. Pack topping over and around apples. Bake pie on baking sheet until topping is golden, about 1 hour (cover top with foil if browning happens too quickly). Cool until warm, about 1 hour.

Recipe adapted from Bon Appétit: Cinnamon Crumble Apple Pie


Eunice LiuAbout the author: Eunice Liu is studying Neuroscience and Linguistics at UCLA. She attributes her love of food science to an obsession with watching bread rise in the oven.

Read more by Eunice Liu


Perfectly Unsoggy Apple Pie

The Science of Pie – June 1, 2014
Honorable Mention Pie
Alexis Cary & Matthew Copperman (Team On the Road)

If you’ve baked an apple pie, you have probably encountered the dreaded problem of a soggy pie crust.

The student scientists of Team On the Road sought to solve this pie-baking mishap by determining the optimal apple slice thickness; the idea was that apple slices of varying thickness would release different  amounts of water when baked, with more water released giving rise to a soggy crust. To investigate the effect of apple slice thickness, they cooked apples of different slice geometries, and measured the “elastic modulus”, which is how much the apple pieces deform in response to a given applied mass.

Team on the Road

(A) Copperman rolls out the pie crust while Cary prepares ingredients. (B) The team presents their pie and poster at the 2014 Science of Pie event. (C) The team tested the elastic modulus of apple slices of varying thicknesses. Photos (A) and (B) courtesy of Patrick Tran. Photo (C) courtesy of Team On the Road.

The team prepared five different samples of apple slices with thicknesses: 3mm, 6mm, 9mm, 12mm, and 15mm. The apples of each thickness group were recorded for mass and elastic modulus before and after being baked for 20 minutes at 375°F.

Avg Elastic Modulus vs. Thickness of Cooked & Uncooked Apple Slices

The elastic modulus is shown as a function of slice thickness for uncooked (blue) and cooked (red) apples.

The thinnest apple slices (3mm) had the least change in elastic modulus. In fact, as the slices increased in thickness, they showed increased deformation in apple shape and texture after cooking. There is an exception for the thickest apple slice (15mm), which the team attributes to the thickest apples not being fully cooked in 20 minutes. Because the thinnest apple slices maintained their firm texture and released the least amount of water, Team On the Road used extremely thin apple slices in their final pie. Soggy pie crusts, begone! Thin apple slices are here to save the day!

Note: While the team cut their slices by hand, we recommend using a mandoline to achieve uniformly thin slices of applies.

Recipe
Perfectly Unsoggy Classic Apple Pie

For the crust:
2 1/2 cups unbleached all-purpose flour, plus extra for dusting
2 tablespoons granulated sugar
1 teaspoon table salt
4 tablespoons cold vegetable shortening, cut into 8 pieces
16 tablespoons cold unsalted butter, cut into 16 pieces
6 – 8 tablespoons ice water

For the filling:
3/4 cup granulated sugar
2 tablespoons all-purpose flour
1 teaspoon lemon zest from 1 medium lemon
1/4 teaspoon table salt
1/4 teaspoon ground nutmeg
1/4 teaspoon ground cinnamon
1/8 teaspoon ground allspice
1 lemon’s worth of lemon juice
2 pounds Granny Smith apples, peeled, cored, and sliced as thin as possible (approx. 1/8” is as small as this team consistently achieved.)
1 pounds Gala apples, peeled, cored, and sliced the same as the Granny Smith Apples

For assembly:
1 egg white, beaten lightly
1 tablespoon granulated sugar, for topping
Adjust oven rack to lowest position, place rimmed baking sheet on rack, and heat oven to 400 °F.

To prepare the crust:
Process flour, sugar, and salt together in food processor until combined, about 5 seconds.  Scatter shortening over top and pulse mixture for 5 times, 2 seconds each pulse.

Scatter butter over top and pulse mixture until it resembles coarse crumbs, about 10 pulses.  Transfer mixture to large bowl.

Add 3 tablespoons ice water over the mixture. Stir and press dough together. (The team used a stiff rubber spatula.)  Add 3 more tablespoons of water and mix until dough sticks together. Continue to add remaining ice water, less than 1 tablespoon at a time, as needed until the dough comes together.

Divide dough into two even pieces. Next, it is very helpful to lightly flour counter, hands, and rolling pin. Roll out dough into 12-inch diameter circles and transfer one of the circles into pie pan.  Let excess dough hang over the edge.  Press dough lightly into the bottom, corners and edges of pan.

Wrap in plastic wrap and refrigerate for at least 1 hour. Wrap the other pie crust dough in plastic wrap and refrigerate.   Refrigeration is important for allowing gluten strands to relax (so the dough becomes easier to roll out), and for letting letting liquids incorporate to moisturize the dough.

To prepare filling:
Mix sugar, flour, lemon zest, salt, nutmeg, cinnamon, and allspice together in large bowl.  Add lemon juice and apples and toss until combined.  Let apples sit in mixture for 5-10 minutes.

To assemble the pie:
Remove pie dough from refrigerator.

Pour apples into the dough-lined pie pan, adding about half of the liquid from the apple mixture to the pie pan. Spread apples so that they create a slight mound in the middle.

Loosely roll remaining dough round around rolling pin and gently unroll it onto filling. Trim overhang to 1/2 inch beyond lip of pie plate. Pinch edges of top and bottom crusts firmly together, pressing overhanging dough towards the pie pan until it lies flush with the pan.

Crimp dough evenly around edge of pie using your fingers. Cut a 2-inch “X” into the upper crust. Brush surface with beaten egg white and sprinkle evenly with remaining 1 tablespoon sugar.

Place pie on heated baking sheet, and bake for 30 minutes. Rotate pie and bake for an additional 30 minutes. Crust should be golden brown. If necessary cook for up to 10 minutes longer.

Let pie cool on wire rack. Serve at room temperature.


Eunice LiuAbout the author: Eunice Liu is studying Neuroscience and Linguistics at UCLA. She attributes her love of food science to an obsession with watching bread rise in the oven.

Read more by Eunice Liu


Harnessing Creativity & The Science of Pie (Event Recap)

On your mark…
Get set…
GO!

As the doors swung open, guests eagerly awaiting the final Science & Food lecture series were transported to a place nothing short of a Pie-Palooza. Twenty student teams stood confidently next to their baked confection and explained to the judges how they employed the scientific method to creatively reimagine the art of baking the perfect pie. Some developed aqueous solutions to modify the flakiness of their pie crusts while others sought to improve filling texture by altering pH levels and used techniques such as microscopy to measure their results. Whatever their approach, the students proved that a little bit of science goes a long way in mastering the craft of pie baking.

Dr. Paul Barber (Associate Professor, UCLA) and Dave Arnold carefully evaluate the students pie presentations

Dr. Paul Barber (Associate Professor, UCLA) and Dave Arnold carefully evaluate the student pie presentations

Special guest judges, Nicole Rucker of Gjelina Take Away and food critic, Jonathan Gold

Nicole Rucker (Pastry Chef, Gjelina Take Away) and Jonathan Gold (Food Critic, LA Times) partner up as special guest judges


Lena Kwak and Dr. Rachelle Crosbie-Watson (Associate Professor, UCLA) take a closer look at student posters

Lena Kwak and Dr. Rachelle Crosbie-Watson (Associate Professor, UCLA) take a closer look at student posters

After the large-scale pie tasting, guest speakers, Lena Kwak and Dave Arnold, took the stage to share their insight on innovation in the culinary laboratory and emphasized how unforeseen mishaps often lead to novel discoveries. Co-Founder and President of Cup4Cup, Kwak discussed how her breakthrough formulation of gluten-free flour was a by-product of her fearlessness to try new techniques and make mistakes in the kitchen. Founder of the Museum of Food and Drink (MOFAD) and Owner of Booker & Dax, Arnold described how curiosity and relentless dedication to experimentation led to the development of many of his out-of-the-box culinary gadgets. Case in point: the Searzall, one of his latest inventions designed for hand-held blowtorches to evenly apply high temperature heat to sear foods while avoiding the remnants of unpleasant aromatics. He also invoked the audience to participate in an experiment where he challenged everyone to digest gymnemic acid, which dulls our sensory perception of sweetness. This exercise was designed to help guests unlock and appreciate the other factors (such as texture) that contribute to our understanding of taste.

Kwak addresses the audience's questions and reveals some of ingredients in her gluten-free flour

Kwak addresses the audience’s questions and reveals some of ingredients in her gluten-free flour


Dave Arnold explains his investigative process to developing his newest product, Searzall

Arnold explains and demonstrates the evolutionary process involved in developing the Searzall


Gymnemic acid, a sweetness inhibitor, made this bag of sweets taste completely bland!

Gymnemic acid, a sweetness inhibitor, made this bag of sweets taste completely bland

Finally, the panel of special guest judges shared with the audience their favorite pies from the student entries and awarded the students with prizes for the “Most Creative Pie”, “Most Qualified to Enter a Real Pie Contest”, “Best Scientific Pie”, “The People’s Choice Pie”, and “Best Overall Pie”.

Tom Folker and Eric Hirshfield-Yamanishi take home the "Most Qualified to Enter a Real Pie Contest" prize

Tom Folker and Eric Hirshfield-Yamanishi take home the “Most Qualified to Enter a Real Pie Contest” prize

Folker and Hirshfield-Yamanishi explored the effect alcohol, specifically Fireball whiskey, had on the overall flakiness of their pie crust and produced a pie the judges thought was worthy of a professional pie contest.

The "Most Creative Pie" went to Ying Zhi Lim and Jen So for their rosemary-infused deconstructed apple pie

The “Most Creative Pie” went to Ying Zhi Lim and Jen So for their imaginative apple pie

These creative young women, Lim and So, took the competition to the next level by presenting a deconstructed, rosemary-infused apple pie topped with a “reverse spherified” lemon zest cream cheese sauce to a create a harmoniously balanced and flavorful treat.

Christina Chung, Tori Schmitt, and Elliot Cheung impressed the judges and won the "Best Scientific Pie" award

Christina Chung, Tori Schmitt, and Elliot Cheung impressed the judges and won the “Best Scientific Pie” award

Chung, Schmitt, and Cheung added different combinations of liquids to generate their pie crust and recorded the amount of force required to alter the elasticity of the baked crust. Ultimately, the incorporation of beer into their pie crust recipe significantly altered texture as measured and quantified by the elastic modulus.

Apple Queens, Alina Naqvi and Ashley Upkins-Scott, stole the show and won both "The People's Choice Pie" and  "Best Overall Pie" prize

Apple Queens, Alina Naqvi and Ashley Upkins-Scott, stole the show and won both “The People’s Choice Pie” and “Best Overall Pie” prize

Naqvi and Upkins-Scott of team Apple Queens took different varieties of apples, including Granny Smith, Red Delicious, Pink Lady, and Fiji, to produce a crumble top pie that garnered praise from both the audience and the judges.

Congratulations to all the winners!

All photos were captured by Patrick Tran. For more images from the event, visit this photo album.


Anthony MartinAbout the author: Anthony Martin received his Ph.D. in Genetic, Cellular and Molecular Biology at USC and is self-publishing a cookbook of his favorite Filipino dishes.

Read more by Anthony Martin


5 Things About Apples

Our third and final lecture, Harnessing Creativity (and the Science of Pie), is coming up fast! At the event, students from the Science & Food undergraduate course will be serving up science and apple pies. To get ready, here are 5 fun facts related to apples:

Apples3


Apples5


Apples1


Apples2


Apples4


Liz Roth-JohnsonAbout the author: Liz Roth-Johnson is a Ph.D. candidate in Molecular Biology at UCLA. If she’s not in the lab, you can usually find her experimenting in the kitchen.

Read more by Liz Roth-Johnson


Chia Seed Apple Pie

Continuing our Science of Pie adventure, we’ve invited Elsbeth Sites of Team Chia to share her pie science project, which examines the use of a very unconventional thickener to tune the viscosity of pie filling.  Elsbeth is an undergraduate student of physiological sciences at UCLA who is passionate about food and writing, especially writing about food.

Have you ever baked a lovely pie, sliced it and placed it gently on your best dessert plates, then watched in despair as the filling fled its warm crust and bled all over the dish? This common and unfortunate experience led our team to investigate the viscosity of pie filling. We hoped to discover a way to produce a pie of perfect viscosity that upon slicing, would not spread over the plate too far, nor be too gelatinous. Most pies contain cornstarch to thicken their fillings. To make our project unique and to put a modern and healthy twist on our pie, we replaced starch with the trendy new superfood: chia seeds.

The outside of the chia seed contains large fibrous molecules called polysaccharides. When the seed is wet, these molecules are exuded from the seed and trap liquid. This allows the seed to hold approximately nine times its own weight in water, causing a bead of gel to form around the seed [1].

Chia seed hydration. Chia seeds can absorb approximately nine times their weight in water. Water absorption creates a mucilaginous gel around the seed. Figures are from [1].

With this knowledge of the chia seed, we posed these questions:

  • How do we create a pie that does not bleed across a plate when sliced while not being overly gelatinous?
  • Can chia seeds be used to increase the viscosity of our pie filling?
  • At what concentration should the seeds be added to the pie to get an ideal viscosity without compromising taste or texture?
Measuring viscosity with the “line spread” test. The line spread test measures the distance a liquid or semiliquid flows across a flat surface. We used a hard, clear, plastic surface marked with concentric circles spread 0.5 cm apart across a 7.5 cm radius. Lines originating in the circles’ center divide the circles into four quadrants. The longest distance traveled by the filling in each quadrant was averaged to find the mean distance that the filling spread.

We defined our perfect filling to be one that spread slightly when placed on a flat surface without remaining too gelatinous and not spreading at all. A traditional apple pie filling prepared with cornstarch spread 5.6 centimeters in 60 seconds. Finding the right concentration of seeds to add was a tedious process, and the heat at which the pie was baked and served greatly affected the pie’s viscosity. As shown in the figure above, our control filling with no thickening agent spread on average 5.9 centimeters in 60 seconds—clearly too runny. The filling to which we added 0.5 teaspoons of chia seeds spread 5.5 centimeters. By evaluating these spread distances and tasting each filling, we agreed that the filling with only 0.5 teaspoons seeds yielded the best viscosity and palatability. Using more seeds than this overpowered the spices in the filling, making the pie taste nutty and giving it a slimy mouthfeel.

Our experiment was successful in that we answered our original questions:

  • Chia seeds can indeed be used to tune the viscosity of apple pie filling.
  • To produce an apple pie of optimal viscosity, replace cornstarch with 0.5 tsp chia seeds per ½ cup of filling. While our pie might appeal to the culinarily curious or health savvy, those who prefer a classic pie may find the seeds of the pie annoying, or might miss the texture that more traditional thickeners like cornstarch or flour provide the filling.

If a seedy apple pie up your alley, here is Team Chia’s recipe for Chia Seed Apple Pie. The truly adventurous might even try using chia seeds in a berry pie where thickening agents are more crucial and tiny seeds are less noticeable. If you do try another variation of a chia seed pie at home, let us know how it goes in the comments below!


Pie Crust
Adapted from Everyday Food: Our Best Pie Crust

2 1/2 cups all-purpose flour, plus more for rolling dough
1 tsp salt
1 tsp sugar
16 tbsp (2 sticks) cold unsalted butter, cut into pieces
4 tbsp ice water, plus 2 more if needed

In a food processor, pulse flour, salt, and sugar several times to combine. Add butter. Pulse until mixture resembles coarse meal, with just a few pea-size pieces remaining.

Sprinkle with 4 tablespoons ice water. Pulse until dough is crumbly but holds together when squeezed with fingers (if needed, add up to 2 tablespoons more ice water, 1 tablespoon at a time). Do not over-process.

Turn dough out onto a work surface; form dough into two 3/4-inch-thick disks. Wrap both separately and tightly in plastic, and refrigerate until firm, at least 1 hour.


Pie Filling and Assembly

5 Granny Smith apples, sliced
3/4 cup granulated sugar
2 1/2 tsp chia seeds
1/2 tsp ground cinnamon
1/8 tsp ground nutmeg
1/2 cup cold water
3/4 cup apple juice

Preheat oven to 350 degrees.

Wash, peel, and core apples. Cut apples into 1/4- to 1/2-inch slices and place in cold water.

Combine sugar, chia seeds, and spices in a large pot with water and apple juice. Stir and cook on medium high heat until mixture thickens and begins to bubble. Boil for 1 minute, stirring constantly. Fold in apple slices immediately and remove from heat.

To assemble pie, roll dough into 2 14-insh rounds. Fit the first crust into the bottom of a 9-inch pie plate. Spoon filling into the pie dish. Cover the pie with the second crust, trimming the overhang to about 1 inch. Press upper and lower crust edges together and flute as desired. Cut steam slits in the center of the top crust.

Bake for 20 minutes at 350 degrees or until crust is golden brown.


References Cited

  1. Muñoz LA, Cobos A, Diaz O, Aguilera JM (2012) Chia seeds: Microstructure, mucilage extraction and hydration. J Food Eng 108: 216–224. doi:10.1016/j.jfoodeng.2011.06.037.

Boozy Apple Pie

On foraging for local ingredients in your college dormitory…

Our Judge’s Favorite winner of the 2013 Science of Pie event showed how beer and vodka affect pie crust color and texture. But they weren’t the only students who experimented with alcohol in their pies. Two other teams—Team Super Rum and the Beam Team—also used alcohol to create flaky, tender crusts. The Beam Team even added Kentucky bourbon whiskey (Jim Beam, of course) to their pie filling for an extra punch of flavor.

So why all the alcohol? According to the Beam Team:

“Our group was inspired by Alex Atala’s process of going out into the Amazon Forest and finding local plants to use as ingredients. As college students, we decided that our ‘native’ ingredient is alcohol since it is easily found in abundant quantities all around us, so we used our two favorite types of hard alcohol: whiskey and vodka.”

There’s another (more scientific) reason for boozing up a pie crust: alcohol creates a more tender, flaky crust than can be easily achieved with water alone. This happens because alcohol and water have very different effects on the formation of springy gluten networks in pie dough.

Gluten develops when two wheat proteins in flour, glutenin and gliadin, are mixed with water. Because parts of these proteins do not like to interact with water, the proteins begin to stick to each other much in the same way oil droplets come together when suspended in water. As a flour-water dough is mixed, the glutenin and gliadin molecules interact to form an extensive elastic network [1].

Gluten development during dough formation. Scanning electron micrographs of gluten networks during early (A), middle (B), and late (C) stages of dough mixing [2]. The development of these gluten networks requires water.

While gluten networks are great for chewy bread dough, they are less than ideal for flaky, tender pie crust. An ideal pie dough has as just enough gluten to hold everything in the dough together. And while gluten development can be minimized by adding only scant amounts of water and handling the dough as little as possible, this is easier said than done.

A more practical solution is to replace some of the water with a liquid that does not promote gluten formation. Unlike water, alcohol inhibits gluten formation. By interacting with the gluten proteins, alcohol molecules limit their ability to stick to each other and form springy networks [1]. Using alcohol in the place of water allows more liquid to be added to the dough while still restricting gluten formation. This results in a softer, more pliable dough that becomes tender and flaky when baked.

TeamSuperRum

Team Super Rum serves their pie and presents their work at the Science of Pie even (left). Test pies made with rum pie crust (top right) or bourbon apple filling (bottom right).

Like the recipe below, the Beam Team paired a vodka pie crust with a decadent bourbon and apple filling. Although vodka is typically used for its subtle flavor, any type of alcohol will prevent gluten formation. As their name suggests, Team Super Rum used rum instead of vodka to create a flaky and uniquely flavored crust. And we bet there are many more delicious possibilities in the realm of alcohol-based pie crusts. If you try this recipe with something other than vodka, share your new pie crust concoction with us in the comments below!


Foolproof Vodka Pie Crust

Cook’s Illustrated, November 2007

2 1/2 cups (12 1/2 ounces) unbleached all-purpose flour
1 tsp table salt
2 tbsp sugar
12 tbsp (1 1/2 sticks) cold unsalted butter, cut into 1/4-inch slices
1/2 cup cold vegetable shortening, cut into 4 pieces
1/4 cup cold vodka
1/4 cup cold water

Process 1 1/2 cups flour, salt, and sugar in a food processor until combined, about 2 one-second pulses. Add butter and shortening and process until homogeneous dough just starts to collect in uneven clumps, about 15 seconds (dough will resemble cottage cheese curds and there should be no uncoated flour). Scrape bowl with rubber spatula and redistribute dough evenly around processor blade. Add remaining cup flour and pulse until mixture is evenly distributed around bowl and mass of dough has been broken up, 4 to 6 quick pulses. Empty mixture into medium bowl.

Sprinkle vodka and water over mixture. With rubber spatula, use folding motion to mix, pressing down on dough until dough is slightly tacky and sticks together. Divide dough into two even balls and flatten each into 4-inch disk. Wrap each in plastic wrap and refrigerate at least 45 minutes or up to 2 days.


Bourbon Apple Pie Filling

2 tbsp all-purpose flour
6 or 7 apples, mix of tart and sweet
1/3 cup sugar
1/2 tsp cinnamon
1/2 tsp nutmeg
1/4 tsp salt
1/2 cup bourbon whiskey
2 tbsp lemon juice
2 tbsp butter cut into small pieces

Preheat oven to 425. Place bottom crust in pie plate.

Peel, core, and halve the apples. Cut into 1/4-inch thick slices, about 7 or 8 cups.

In a 4 quart saucepan, whisk together sugar, flour, cinnamon, nutmeg, and salt. Whisk in bourbon whiskey and lemon juice until evenly blended. Cook over medium heat, whisking frequently until the mixture boils and thickens slightly. Add apples and stir until evenly coated. Continue cooking, stirring continuously, for 3 minutes. Set aside to cool, stirring once or twice for 20 minutes.

Pour apple mixture into the pie shell, mounding apples slightly in the center. Dot with butter and add the top crust. Cut several steam vents into top crust.

Bake 25 minutes at 425. Reduce temperature to 350 and bake 45 minutes longer or until crust is brown and juices are bubbling.

Serve warm or chilled with whipped cream or ice cream.


Online Resources

  1. Pie crust recipe from Cook’s Illustrated via Serious Eats
  2. Bourbon apple pie filling recipe adapted from Group Recipes


References Cited

  1. Technology of breadmaking (2007). 2nd ed. New York: Springer. 397 p.
  2. Amend T (1995) The mechanism of dough forming: Efforts in the field of molecular structure. Getreide Mehl Brot 49: 359–362.

Liz Roth-JohnsonAbout the author: Liz Roth-Johnson is a Ph.D. candidate in Molecular Biology at UCLA. If she’s not in the lab, you can usually find her experimenting in the kitchen.

Read more by Liz Roth-Johnson


Pie Science & Fried Fish

NYTimesPie

Amy Rowat dissects the science of pie for the New York Times, while Harold McGee explains how vodka makes a light, crispy batter for frying fish. Apparently pie crust isn’t the only dough that benefits from a little alcohol! Read more

10 More Things You Should Know About Pie

It’s summer. Berries and stone fruits abound, and so the season of pies continues. And we continue to think deeply about the science of pie. There has been intense interest in pies these past few months: first at the Science of Pie event; next at the World Science Festival’s Scientific Kitchen workshop at Pie Corps in New York; and most recently the New York Times Pie Issue. But we believe you can never know too much about pie. Here are 10 more things we think you should know…

WSFPieScience1

The World Science Festival’s Science of Pie workshop featured Amy Rowat with Pie Corps’ Cheryl and Felipa and special guest Bill Yosses, White House Pastry Chef and mastermind behind some of the best pies that Barack Obama has ever tasted. Here Cheryl, Felipa, and Bill dish out apple pie for the workshop participants.

WSFPieScience2

Science of Pie workshop participants deeply engaged in the science (and eating!) of pie.

1. A bit of high school chemistry goes a long way when baking pies.
The ideal gas law (PV=nRT) tells us that the volume of an air pocket gets bigger with increasing temperature. In the oven, molecules get more energy and start moving faster and faster, causing air pockets to get bigger and bigger; this can result in an inflated pie that collapses once you cut into it. At the same time, apples lose water, most of which gets converted to steam. Consider that a water molecule takes up about 1700 times more volume in the gas phase than in the liquid phase: if your crust were completely impermeable to water and all the steam got trapped inside, your pie would become much larger than your oven! Luckily much of that steam can escape through the crust and through steam vents. (This is also a good reason to be sure to avoid air pockets when you lay your crust into your pie tin!)

2. There is an art to cutting your fruit for a pie filling.
The way you cut your fruit is important. Smaller pieces of fruit will cook more quickly, but they also tend to lose more liquid since they have a higher surface-area-to-volume ratio. The geometry of your fruit pieces is also important for packing the filling into your pie. After placing your fruit slices into the center of the pie, pat them down to make sure they all like flat. This will create a pie with a lovely cross-section of layered fruits and, more importantly, will help to avoid air pockets that can expand in the oven.

3. Sometimes the best pie is a day-old pie.
Temperature is important for pie texture. Eating your pie the day after you bake it allows plenty of time for the pie to cool down and the filling to “set”. Because molecules flow more quickly past each other at higher temperatures, hot pie filling straight from the oven will be more runny; as the pie filling cools, starchy molecules like cornstarch and flour spend more time interacting with each other. As the pie cools, the pectin molecules of your fruit also spend more time interacting with each other. This results in a more solid, gel-like filling that will take longer to seep out of the pie when it is cut and served on a plate.

4. Think of butter as a gas.
Butter is really just a bunch of teeny tiny water droplets dispersed in a matrix of fat. In the oven, these water droplets convert from liquid to gas. This means that the chunks of butter you can see in your dough are really just big pockets of air waiting to happen. More air = flakier crust! While butters with the highest butterfat content are generally synonymous with the highest quality butter, when it comes to baking pie a slightly lower fat content, and higher water content, may be a good thing.

5. Wash with egg for a darker, more delicious pie crust.
All those lovely color and flavor molecules in a nicely browned pie crust are the result of the Maillard reaction, a chemical reaction that occurs between amino acids, which comprise proteins, and sugar molecules like lactose or glucose. Brushing an egg (protein) on your pie crust before baking is a great way to add extra color and flavor. For extra browning, mix some heavy cream into your egg wash (more protein plus lots of lactose).

WSFPieScience3

Look at all those Maillard reactions!

6. Turn up the heat!
Maillard reactions happen faster at higher temperatures. Keep your oven hot (375F or so) to brown your pie that extra bit more. Another strategy is to start off at 400F, then turn down the temperature to 350F.

7. Bake your pie in parts.
A major challenge in baking pie comes from its complexity: you’ve got a crust that should be brown and crisp together with a filling that largely contains water. When contending with fruit pie fillings, one strategy is to prebake the bottom crust to help prevent it from becoming soggy. In this process of “blind baking,” don’t forget to prick holes in the bottom of your crust so the water vapor can escape. Filling your pie crust with pie weights or dried beans during this process can also help prevent layers of your wanton bottom crust from puffing up. Pie master Bill Yosses suggests taking this sequential baking process an extra step further: after the bottom crust has baked, it can be stitched into the sides of a crust using extra dough to “glue” the bottom to the sides. In the spirit of experimentation, this could be an interesting new method to try.

8. Create a pie crust with your “perfect” texture.
Typical attributes of a “perfect” pie crust include: flaky, tender, brown, and a little crispy. While the optimal texture of a pie crust is a deeply subjective and personal matter, here is a rough guide to how you can tune your pie crust texture simply by considering how you work your fat into your flour. For taste, color, and texture, we prefer butter, but shortening or lard can also be used.

  1. You want your fat to be solid when working it into the flour. Remember those little chunks of fat will become pockets of air in your crust! In a liquid form, it would coat the flour too evenly, resulting in a less flaky crust.
  2. Because butter melts around 30–32 degrees Celsius (86–90F), it can be tricky to make sure it remains solid while you work it with your hands (about 35 degrees Celsius or 95F). Prior to making your dough, cut your butter into small 1 x 1 cm cubes and place in the freezer for about 10-15 minutes.
  3. For a crust that has more form and larger flaky holes, work your very cold butter into the flour until you have a distribution of butter pieces with various sizes: some should appear the size of peas, others the size of almonds. When you work your butter in to achieve these sizes of chunks, much of the butter will get worked in so the rest of the dough will appear as coarse wet sand.
  4. For a tender and flaky crust you need a decent coating of fat around your flour. To achieve this, try the two-step method: (i) Divide your butter in half: cut one half into small cubes, and keep the remaining half in stick form. Place both halves in the freezer to ensure they are very cold. (ii) Work the stick of very cold butter into your flour by grating it in with a coarse grater. Work in thoroughly with your hands until the mixture has the texture of a coarse sand. (iii) Add the remaining half of your butter in cubes and work in with your hands until the largest pieces are about the size of peas. The theory here is that completely coating the flour in oil helps create a more “tender” crust.
  5. If you want to avoid getting your hands messy, or want to minimize heating of your butter, use a pastry cutter, or two knives held side by side, to work the butter into your flour.

9. Different types of flour create different types of pie crust.
What flour is the best flour for pie crust? This is a contentious question that has a variety of answers depending on personal preference, but the type of flour you use can have a major effect on the final texture of your crust. The protein content of flour, based on the type of wheat the flour was made from, will affect the extent of gluten formation in your dough. While springy networks of gluten proteins are great for chewy breads (bread flour has particularly high protein content), they can make pie crust dense and tough. Flours with lower protein content, such as pastry flour or cake flour, will create less extensive gluten networks and can produce a more tender crust. However, the pie crust ultimately needs to be formed into a dough, which can make it a challenge to work with a fragile dough that can result when using a low-protein content flour.

10. Almond extract tastes great in a fruit pie.
What more can we say? Nuts and fruit taste great together! A bit of almond extract is a delicious complement to apples and apricots alike.

AppleFoodPairing

And it’s not just almonds—lots of fruits and nuts go great with apples. This food pairing map from www.foodpairing.com is full of interesting flavor combinations.


Amy RowatAbout the author: Amy Rowat is a professor at UCLA. She began experimenting with food as a toddler and continues to research soft biological matter in the lab and kitchen.

Read more by Amy Rowat