Merry Christmas everybody! Despite still being in a pandemic, the ISTS team hopes you still feel some Christmas spirit. It is, after all, the season of gifts and joy. But if you’re feeling down in the dumps like I was – knowing I’m missing out on Christmas markets overseas – the ISTS team has just the activity to bring your spirits back up!
This Christmas, we are exercising our brains with some engineering and food science as we attempt to build a Gingerbread House.
First, we make some strong gingerbread – the fundamentals. Its dough needs to be tough with springy consistency and less moisture so that it can stand and withstand the weight from its roof. We don’t want our walls to crack or collapse, thus the use of high protein content like flour that contains more gluten. This would make denser and stronger products. We also added ammonium bicarbonate, which is a leavening agent that makes our product lighter and crunchier. This is due to its crystals decomposing in the oven and leaving miniscule air cells so that moisture easily escapes. Be prepared for its strong smell which will of course disappear after baking.
Ingredients (for 3 houses as per given measurements, with extra for additional gingerbread men):
Heat water, honey, and sugar to boil and leave to cool. Use an ice bath if you’re tight for time. While waiting, mix eggs, spices, baking soda and ammonium bicarbonate together. Add and mix in the cooled sugar mixture. Lastly, add in the flour. Refrigerate for 24h or overnight.
Rolling out the dough and cutting out the pieces is best done in a cool environment. If you’re in hot Singapore, work with a good amount of dough, leave the rest of the dough in the fridge, and switch whenever the working dough gets too sticky. Use the measurements below and bake at 170 degrees until the underside of the pieces no longer stick to the baking paper lined on the tray.
Next, we need ‘glue’ to hold our house together. This is where icing comes in. The icing mixture needs to be whippy enough to have the pieces stick together before hardening. The proteins in egg whites are responsible here as they denature – meaning they change the structure of the proteins as the bonds within the molecules are broken by force. They then coagulate and form trapped air bubbles, giving the icing a stiff texture that allows it to hold things in place.
Mix the egg white and icing sugar together until completely white and thick. If you find that it is still too runny, add more icing sugar. Place in a piping bag for easier construction later.
From the weight of the gingerbread, to the dimensions of the house and the angle of the roof, a lot of thought goes into building a house…. but we are going to do our best here!
Firstly, the walls should be made of thicker slabs of gingerbread for better contact between pieces as the larger surface area would mean added friction to keep everything in place. It should also not be too tall as that would result in a higher center of gravity. For the roof, an isosceles triangle would be the best shape as it distributes the weight evenly. A flatter rooftop i.e. a wider isosceles triangle would be better as the weight would be more spread out. Finally, we glue everything together with icing as it dries into a hard, unmovable substance that keeps the pieces in place.
And if you’re planning to decorate your house with lots of candy, be sure to spread it out over the surface and ensure that each piece is not too heavy. Watch how we do it here!
And there we have it! Our very own gingerbread house. Oh, don’t you feel the Christmas spirit now! It almost feels like a fairytale. Now to demolish it in the best way possible… by eating it!
Engineering the Perfect Gingerbread House | scienceandfooducla (wordpress.com)
Gingerbread House Recipe | Food Network
Physics 111: Fundamental Physics I: Structural Integrity of a Gingerbread House (colgatephys111.blogspot.com)
The science behind gingerbread houses (pitsco.com)
Written by Lydia Yasmin
Illustrations by Lee Ai Cing