This 3D-Printable "Oreometer" Is the First Tool in the Science of "Oreology," Cookie Fans

A team from the Massachusetts Institute of Technology (MIT) has put science to work in what could well be the entirely novel field of Oreology, building a measuring device dubbed the Oreometer to figures out exactly what happens when you twist Oreo cookies apart to get at the delicious inner layer — and why the filling tends to stay attached to just one of the two cookies.

"There’s the fascinating problem of trying to get the cream to distribute evenly between the two wafers, which turns out to be really hard," explains undergraduate student Max Fan, a mechanical engineer who set about trying to find an answer to the question of single-side adhesion in Oreo fillings — and why older boxes don't show the same behavior, leaving the filling on both sides instead.

To really investigate the problem, though, required more than a box of cookies and a glass of milk. It needs the Oreometer, a 3D-printed and now open source gadget that can have its torque calibrated via the application of pennies and rubber bands to find out just how much force it takes to split an Oreo in two.

It also required the use of a lab rheometer, a device for testing fluidic materials — including, now, the cream filling in an Oreo. With Oreos glued to the device, varying degrees of torque and angular rotation were applied — resulting in the discovery that in modern boxes the filling stays almost always on one side, and that in rheological terms the filling is "quantitatively mushy."

First and corresponding author Crystal Owens also has advice for those looking to maximize their Oreo experience: "If you try to twist the Oreos faster, it will actually take more strain and more stress to break them," Owens explains. "So, maybe this is a lesson for people who are stressed and desperate to open their cookies. It'll be easier if you do it a little bit slower."

It's not all about snacks, though: Owens claims that the research into Oreo fillings can have wider application. "My 3D printing fluids are in the same class of materials as Oreo cream," she explains.

"So, this new understanding can help me better design ink when I'm trying to print flexible electronics from a slurry of carbon nanotubes, because they deform in almost exactly the same way."

The team's work has been published in the journal AIP Physics of Fluids under open-access terms, while details on printing your own Oreometer — which its creators note is compatible with "other sandwich cookies and snacks" — and design files are available on the project's GitHub repository under the permissive MIT license.