Note: if you’d like to read a shorter version of this cake without the swearing, go check out my wife’s take on it over at flourarrangements. Plus, hers has corndogs.
A few years ago, when my daughter was about three and had a big enough vocabulary to say some really funny stuff, she was babbling in the backseat of the car. Suddenly, she pops out with “I want to build a gingerbread…” and then gets lost in thought for a half beat. It was long enough that I thought she was searching for the word, so I was about to fill in with “house” when she finishes decisively with “computer.”
A gingerbread computer? It blew my mind. While I was cracking up, all I could think to ask was, “What OS will you boot on that?” Which was not the sort of arcane technical detail she gave a shit about. I think she really was thinking about all the candy she would use to lay out the keyboard.
Anyway, flash forward, and she’s got an eighth birthday coming up. I like birthdays. I like going over the top on cakes. Really, the cakes are my wife’s deal, but I like staying up ’til 4:00 am drinking beer helping to wrap fondant around a volcano wondering if I can make it blow up. This year she had her heart set on a dolphin cake which seemed like an okay idea except that she had visions of a leaping dolphin with all sorts of overhanging bits that were probably going to be impossible to execute in cake and marshmallow fondant. Somehow I managed to brag that if she wanted to skip a cake and go for gingerbread, I could make anything. What the hell… did I just paint myself into a corner trying to show off for a seven-year-old? Apparently.
The definition of “anything” that we end up with is a Ferris wheel. I even boast I can make this shit go ’round and ’round. My wife has a sort of horrified look on her face that’s part “don’t you dare fuck up a little girl’s birthday with some of your Mankitchen shit,” part “holy crap, can you really do that?” She’s pure practicality though. She wants to know what part we’ll eat.“Oh, we’ll put cupcakes going around and around on the wheel.” Now there is stunned silence; maybe everyone else had been thinking of some rinky-dink gingerbread cookie about the size of a cupcake, but I just upped the game. Eliza absorbs this craziness for about 10 seconds before she is on board 100 percent.
I’ve got this idea like one of those Fisher Price toys I remember from when I was a kid… creepy, round-headed dolls going around on their cupcakes with candles poking out of their heads. Of course, a cupcake is going to set the scale for the whole thing. It’s got to be big enough for a bunch of cupcake cars to look legit. I grab a cupcake and a big scrap of cardboard and start laying out a model. I need to move this idea from craziness to vision fast, because I’m pretty excited about it. Plus, I don’t want to fall back to having to cantilever a leaping dolphin. Full steam ahead.
The more I think about this, the more stoked I get. I start thinking about gingerbread houses I used to make and how strong the crap is. I can do it; I’m not content to think about doing the wheel, but the whole support structure out of gingerbread. This isn’t a birthday cake, this is poetry. Think about a haiku; you’ve got to say something, but there are rules about syllables or whatever, so you have to keep mulling over words to say whatever it is and still have it be right. Everything has to be edible (I grant myself that the motor can be toxic, though I toy with using a lemon for a battery). I’m picturing one of those obscenely large candy canes as the axle, smaller ones for spokes. This cake is pure haiku.
Actually, it’s more like a sonnet. We’ll be in for the long haul on this one. I fire up Sketchup and start laying shit out. I actually hate Sketchup, but it’s the only thing I’ve got on my laptop that can do this. I’m going to have to do a lot of baking, so I need to break it down to manageable chunks. I plan a bunch of wedges and size them so they can fit on 8 1/2 x 11 paper so I can print them out. I plan on little cars that can hold the cupcakes on their ride, printed out on Adam’s Makerbot. This thing is going to be epic.
When I describe the plan to Adam, and show him the cut diagram, he flashes brilliance. Why roll out gingerbread and cut it, he asks? Instead, let’s make a custom pan that will make perfect pieces every time. I export my diagram as an STL file and take it over to Adam. We dig out a grungy piece of 3/4-inch aluminum, fire up the Tormach CNC mill, and away we go.
I mix up a batch of gingerbread dough out of the Joy of Cooking, press it into the pan and bake it. It mostly works, but it needs more butter and flour to get it to pop out of the pan, but it tastes good, and looks awesome. A cool aspect of this custom-cut pan is that I put in little nubs to mark where I want the cross braces to connect. This ought to ensure they line up. It takes a few tries, but I eventually get it down: butter the pan (better than oil… I didn’t try cooking spray), add some flour and shake it around. Press the dough in firmly, and squish it a lot to fill in any trapped pockets. Then I rolled it flat (Adam suggested cutting a new pan with a sharp edge that would self-trim the dough, but I don’t really need two of these pans. I’ll be damned if I’m making another one of these things). It turns out a lot better if I stick in the fridge for 10 minutes to let the dough relax after the squishing. Then I pop it into the oven at 375° F for 25 minutes. Once it comes out, I let it sit for five minutes and run a knife around the edges of the pan. After that, I give it another 20 minutes and carefully work it out of the mold. Crap, I’m tired just typing this, and I had to make about 25 of these damn things. A few broke. A few stuck before I worked out this schedule. They took about an hour each.
Okay, so I finally had eight good ones and decide to start gluing the wheel together. The secret of this whole thing is royal icing: 155 grams of powdered sugar, one tablespoon powdered egg whites and two tablespoons water. This stuff sets up like concrete. I once made a gingerbread house and got a little nervous that it was flimsy, so I filled all the corners with a wedge of gingerbread and a crapload of royal icing. Later on, I couldn’t break the corner pieces down. I think I might have stepped on them, although I might be making that up.
The glue-up went well: I butt-joined the wedges together and then added a one-inch wide strip on top of the seam. If my recollection serves, this thing should be stiff enough to roll like a wagon in a day or so. Not so much, it turns out. My previous experience with gingerbread is all from California; here in the Pacific Northwest, we’ve got this humidity thing going. The first wheel feels like a bike tire without the spokes inside. Birthday is in four days. Uh oh.
I take all the wedges that are baked and not broken and pop them back in the oven for another 20 minutes. They come out hard as rocks. Some of them crack, but those that don’t feel a lot better. I take the wobbly wheel and chop the frosting off with a bench scraper. I manage to salvage about four of the wedges, which I rebake. Okay, I’ve got this wedge thing down. We’re on a roll. This is totally going to work.
Meanwhile, I’m dicking around with the cars for the Ferris wheel. I mean, the cupcakes have to ride on something, right?
My plan is to print it on Adam’s Makerbot, but then I give it another look and realize I’m sniffing glue if I think I’m going to be able to print 1/8-inch thick arms that are 3-inch tall. So I have to spend another few hours breaking it into pieces that can be printed flat and then snapped together. I give it a try, and it turns out that I don’t actually know how to use the Makerbot. Not really a problem except that time is wasting, and I’ve got a lot of gingerbread to make. Yeah, and I need to glue it together into a damn wheel that can support cupcakes.
Adam spends some time optimizing the printer for the new PLA that he just got, which helps a lot. But then he gets a good print, and I realize that the tabs that are supposed to hold the whole thing together are too damn small to make on a printer with this low resolution. Even if they work, they couldn’t hold a cupcake. I decide to just come up with a new design later. Adam is going out of town, but what the hell; he shows me where the printer software is, I gots the interwebs, no problem.
I get the first wheel glued up, and I’m back on vision. I can easily pick it up by the rim with hardly any flex. It’s 21 inches of gingerbread awesomeness. This is totally going to work.
Friday night is crunch time: I have to bake three more wedges, glue up the final wheel, redesign the cars and print them. That leaves me Saturday to turn this collection of parts into a Ferris wheel. My wife is giving me dirty looks and asking why she didn’t just make the damn dolphin cake. Even my daughter is looking worried and saying things like “It’s okay if it doesn’t work, daddy, I’ll still love you.”
It’s a long night. I eventually get a rhythm: roll out some dough, tweak the car design, pop the dough in the oven, run over to the Makerbot and try to get it printing, run back over to take the thing out of the oven, tweak the design, open another beer, try to get the new design to print, pop the wedge out of the mold, etc. By about 1:00 am, I’ve got enough wedges and no cars. For some reason, Sketchup is determined to fuck me; when I export the file, it turns inches to centimeters and my 3-inch parts ends up being 70 inches which, even when I scale it, causes the Makerbot to bang its head off its walls. I give up on the cars. They were coolness, but not really critical. Making the thing out of gingerbread might be poetry, but gingerbread and PLA? Not poetry.
I’m gluing the second wheel up, and then I break a wedge. It was probably good; I was trying to decide if a crack was critical and, well, it turns out it was. Okay, roll out another one. Crack another beer. One more try on printing the car. I finish gluing the wheel by about 3:00 am and hope it has time to harden before I put it all together. By 7:30 am, it’s feeling pretty rigid. I jostle the edge and it’s solid. I lift up the edge a bit and, oh hell, it busts into three pieces. But it’s okay; it’s better than the eight I started with, right? Mix up some more royal icing and glue it again.
Now I’m worried. The plan was to have the two wheels held apart by candy canes, pure edible awesomeness, remember. It also means royal icing has to resist all of the shear forces of a wheel spinning with cupcakes hanging from it. Yeah, that ain’t gonna work. Fuck poetry. I head to the hardware store. Carriage bolts aren’t edible, but they just might do the trick. I come up with each wedge sandwiched between two big washers with a nut on each side. I want to use nylon ones, but Ace wants $.80 for a big nylon washer and I need 16 of them. This thing is feeling doomed at this point, I may as well see if it can support two pounds of metal. The rhyme and meter of this project called for the support structure to be made of gingerbread. But really, who can tell the difference between gingerbread that’s burnt to a crisp and Douglas Fir? Call it poetic license. I whack out a quick frame with some 2x2s.
Surprisingly, the bolting goes way better than I expected. I balance the upper wheel on chunks of foam and go to it. After about three, I realize that this is putting a lot of stress on the bolts, so I slide some cardboard under it. Lots of sketchy moments moving this whole thing, but at the end, it’s bolted together and feels kind of rigid. Time to to get really sketchy and drill a hole in the middle for the axle. Originally, this was going to be one of those giant sugar sticks that I remember wanting as a kid, but no, poetry is dead. I use some scrap acrylic rod I have lying around.
I’m clearly making the grandparents nervous. They’re used to my crazy shit, but they are here for their granddaughter’s birthday party and clearly don’t want to watch the cake self destruct. I get them to help decorate the wheel, though, and they start to see how cool this thing could be. With M&M’s all over the wheel, it looks like a carnival ride, right?
I keep putting off the moment of truth because there’s a lot to think about. I’ve eventually got to take this nicely-braced wheel that’s sitting horizontal and flip it 90 degrees and then hope it doesn’t just collapse. Although if it does fall apart at this stage, it would be nice to have enough time to bake a cake before the party. I have to set that against the fact that the longer it sits, the stiffer the frosting is going to get. Plus, I’m worried that it will creep if it’s hanging in a new position. I eventually decide it’s too late to bake a hail Mary cake anyway and wait until right before the party.
Astonishingly, it flips with no worries. It doesn’t crack or creak or stress me out. It even spins pretty well. If it survives until the party, I’m good. I hang the cupcakes from the carriage bolts with pipe cleaners. This gives me plenty of chance to curse Sketchup, Makerbot, and my own procrastination for not letting me printing the cars. That would have saved me an hour of oh-so-carefully twisting pipe cleaners around the bolts waiting for this thing to self destruct at any moment. All done, it just looks awesome. I abandon my plan to hook up a motor to spin it; partially because I’d mounted the drive gear on the wrong side so the belt would be right in front, and partly because I was afraid it only had a few turns before it self destructed.
By cake time, everyone had ooh’d and aah’d and Eliza would probably forgive me if I busted her cake, so I picked it up and moved it to the middle of the party. Suzanne stuck candles in all the little cupcakes decorated with fondant, and we set Justin and Neil to work with lighters. It was kind of funny because they were working so fast that they didn’t notice Eliza blowing them out as fast as they lit them.
And all that stress and worry? Wasted. Totally wasted. With the candles out, this project was over. I grabbed the rim and gave it a good, hard shove. The wheel swung so fast that the cupcakes were standing straight up on the top and some of them went flying, but the wheel was solid. I declared to the kids that it was open season on gingerbread, and some of them couldn’t even break it. With about five of the 16 wedges cracked and broken, it still spun pretty smoothly.
Back to the original premise, you can build pretty much anything out of gingerbread. Not sure about a computer, but maybe. Given some time and low humidity, I wouldn’t have needed the wooden frame. I could have made the little cars out of gingerbread, too. And the cupcakes should have been soft, squishy gingerbread cake instead of Kahlua chocolate. That would have been poetic.
3 thoughts on “Structural integrity – can you really build that out of gingerbread?”
I think this about the coolest thing ever. You really are an amazing dude and I am glad we get to share in your endeavors!!!! The blog highlights your amazing talents and obsessions.
Wow – I was thinking of making a gingerbread ferris wheel myself and googled to do the research. I love how you’ve done yours – it’s so large! I’ll be doing mine probably half the size of yours and the wheel in one piece rather than wedges. Hopefully it turns out as successfully as yours did!