It might have been Christmas Day yesterday but that doesn’t mean the season is over (today is the second day of Christmas after all). And that means lots more food to eat, including Christmas cookies. But how do you get the most out of a batch? Norwegian chemist Martin Lersch has a solution.
He wanted to solve the problem of making Christmas cookies using a cookie cutter that wasted the least amount of biscuit. He blogged about his project on his site, Khymos, where he also examines the “chemical curiosities of the kitchen”.
According to Lersch, most Christmas-related shapes are inefficient, all except one: the humble Christmas tree. Lersch’s Christmas tree tessellates meaning it can fit next to each other without leaving any gaps or overlaps.
When cutting cookies from a rolled out dough or placing cookies on a sheet for baking you actually attempt to solve a mathematical problem known as a packing problem. The purpose is to maximize the distance between the cookies and maximize the size of the cookies, paying attention that the cookies should not touch. Many will perhaps start with a square packing (see below), but soon figure out that a hexagonal packing will fit even more cookies onto the rolled out dough or onto the baking sheet (especially when the dough/sheet is large compared to the cookies).
Lersch also opened the challenge to the public to find their own tessellating Christmas shapes and said he might have his cookie cutter 3D-printed.