Picture of giant fractal pecan pie
for thanksgiving 2k4 we opted to construct a very large pie.

based on a prototype the previous year we were aware of a fundamental limitation of large pies, namely the crust to filling ratio. for traditional circular pies of radius R, the amount of filling scales as R2 while the crust only scales linearly so as the pie grows larger, the flaky crust is completely dominated by the creamy filling.

our solution was to construct a pie pan in the shape of a koch snowflake (whose perimter obeys completely different scaling laws), fill it with delicious pecan pie and bake in a custom backyard oven.

Step 1: Layout design

Picture of layout design
the layout was determined by two constraints:

1. the finished product had to fit in the transport vehicle. this gave an maximum outside diameter of around 50 inches, conveniently close to the 24x48 inch sheet metal available at the local hardware store. this set the initial side length L of the largest triangle.

2. we only had access to crust of a finite constant thickness so the smallest triangle had to contain some reasonable amount of filling. (L/3)niter > minimum acceptable edge length suggested that we go no deeper
than 4 iterations.

A template covering (1/12) of the entire perimiter made reasonably quick work of laying out the pie pan edge.
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canida6 years ago
This Instructable was featured on NPR's Here & Now on November 24, 2008!
JennaWrites5 months ago

While the pie is amazing in and of itself (my jealousy knows no limits - having nut allergies SUCK around the holidays as my family makes absolutely amazing pecan pies. There are days I seriously ponder the pros/cons of saying to heck with it and having a slice, after all, I've GOT an epipen... haven't buckled yet, but the idea is always there) the part that has me furiously scribbling and trying to work out some details is the giant oven you created. I'm suddenly seeing potential for backyard pizza parties where one pizza really IS all that is needed for 20 people! Or perhaps an epic brownie to end all brownies?

char67087 months ago

kochs curve

This is super cool, and now I want to make decorative fractal art!

Best paragraph I've read in a while. Found my way through: http://felixsalmon.tumblr.com/post/13577123646/the-thing-they-dont-tell-you-about-fractals-is
jusbeachy3 years ago
That's just totally AWSOME !!!!
Thanks so much for sharing it all, the PIE PAN, the OVEN ,
& most of all THE PIE !!! Sincerely, Jus Beachy
ferrocene9 years ago
Beautiful pie! Granted, you've achieved a pie with a more crustacous scaling law, but how do you serve it in human-sized pieces, assuring each diner a similar quantity of crust? The problem would be easy to fix in a purely mathematical sense, in the same way that a sphere can be dissected and reassembled into two spheres. The trick doesn't work for real representations of spheres, and sadly, probably wouldn't work for real pies, either. :( Maybe a Sierpinski gasket-shaped pie pan?
Sierpinski gasket pie...

Maybe a Menger sponge cake (or Menger spongecake, w/e)

Of course it would soak up a lot of rum (infinite surface area) but would not be very filling (with zero volume)
EnigmaMax4 years ago
dear god... infinite pie...
i understand what you are trying to do with the whole "filling dominates crust" thing, but wouldnt the midlle be dominated? i guess you could solve this by making the center a bit thicker than the edges. Please reply, as i would like to know what you think about it. Thanks, -Darthpotato
rxtrekker5 years ago
i bow down to you.  totally incredible!!!!!!
Daddydano5 years ago
You guys are incredible. Awesome mind power combines with the love of good food. I am going to connect this up to my face book. You guys deserve others to see the true powers of Geeks in action (I meant this in a totally nice way). Have a great Christmas!
MT-LB5 years ago
a little hard to cut, maybe, but this is genius
eucharist5 years ago

Lol - how to instructify a pecan pie!

texabyte6 years ago
if i were you for the oven I would take some fiberglass insulation and put that in the cinderblocks to help hold in heat
ravebot6 years ago
yummy looks like a snowflake
puffyfluff7 years ago
Awesome! This will be a great way to share my love of fractals.

90% of it will go to waste, though...
turkeytek, I have just discovered your genius for food. You get an A+ for this one. I'm wondering if another piece of durock under your oven rack would help diffuse the heat enough to avoid hot spots. Perhaps a couple of inches below the rack to ensure good airflow.
turkey tek (author)  Poppa Chubby7 years ago
that might work, but i'm not sure durock could stand up to the heat. it may even have some plastic mesh inside. i guess a giant baking stone would do the trick.
Or even some strategically placed cinder blocks. D'ya think a large piece of heavy steel or cast iron might do it? Something similar to say, a manhole cover? I might have to make a giant oven. Just because it can be done.
PiMan3147 years ago
PiMan approves!
Sgt.Waffles8 years ago
HAHAHAHAHA! You look like eric forman off of that 70's show:

Wait, which one? I always think elf looks like Harrison Ford, but I'm partial. Maybe you were talking about tek. Or the pie? I don't think the pie looks like Eric Forman.

karen6088 years ago
dang! super pie, wall art.... so when are you opening the art studio cafe? cool!
SugarTeen529 years ago
Ewilhelm, you like the edge? (sorry for communicating through comments to ewilhelm, turkey tek!) Turkey Tek, looks delicious! How long did it take to do this again?
turkey tek (author)  SugarTeen529 years ago
a month worth of friday nights. maybe 15 hours shaping the sheet metal and folding up the edge. another 5 hours futzing around with the welder and 9 hours to build the oven, mix ingredients and bake it.
was it worth it, for the pie?
pecan pie is worth anything.
That's... pretty long!
One of my all-time favorites...
Vendigroth8 years ago
how about a mobius-shaped pie next? i really like this, it's somewhere beyond cool
Berkana8 years ago
Wow, this is nerlicious! I salute your nerditude.

4 _
all_thumbs8 years ago
Finally a practical use of that fractal ho-ha.
elfpower8 years ago
It's not true that we didn't have a backup plan. Our backup plan was to make Thanksgiving Jello.
turkey tek (author)  elfpower8 years ago
where by jello you mean a soup of pecans, corn syrup, sugar and uncooked eggs.
ewilhelm9 years ago
Incredible! I assume you still have the pie pan somewhere in storage? Maybe once the glow of the Maker Faire has worn off, Instructables could sponsor a Bay Area Makers giant pie eating party? We could host it at Squid Labs, in Emeryville. I'll bet this design would also be useful at more conventional sizes. I know I always fight for the edge pieces of lasagna, brownies, and apple crisp.
It would seem, that for people who like corners, you should make pies of the same shape, but 3-6 inches in diameter. This way, each person gets their own pie, and crust!
turkey tek (author)  ewilhelm9 years ago
thanks. now included is a picture of the pan's final resting place. i'm sure it is still servicable if the opportunity should arise.
xrobevansx8 years ago
is it safe to have that LP hose *in* the oven?
turkey tek (author)  xrobevansx8 years ago
the temperature in the oven is only 350-400 degrees F. i think the thick rubber hose can generally withstand these sort of temperatures. this hose had an id printed on it that allowed us to look up the temperature rating.
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