MIT researchers study why Oreo’s cream filling only sticks to one cookie

Researchers devised an “Oreometer” to help with their study.

CAMBRIDGE, Mass. — Mechanical engineers at the Massachusetts Institute of Technology put an Oreo’s cream filling through a battery of tests to understand what happens when two wafers are twisted apart according to their study.

When you twist open an oreo cookie to get the creamy center you are mimicking a standard test in “rheology---the study of how a non-Newtonian material flows when twister, pressed, or otherwise stressed,” said a spokesperson from MIT.

But researchers conducting this study want to know why the cookie’s cream stuck to just one cookie when twisted apart.

“Videos of the manufacturing process show that they put the first wafer down, then dispense a ball of cream onto that wafer before putting the second wafer on top,” says Crystal Owens, an MIT mechanical engineering Ph.D. candidate who studies the properties of complex fluids. “Apparently that little time delay may make the cream stick better to the first wafer.”

Researchers devised an “Oreometer” — a device designed to split the cookie with a scientifically precise amount of force using pennies and rubber bands.

They hoped with the perfect twist the cream filling would evenly distribute between cookies, but it was proven that it could not happen.

Ultimately the researchers went through about 20 boxes of Oreos, including regular, Double Stuf, and Mega Stuf levels of filling, and regular, dark chocolate, and “golden” wafer flavors and they found that no matter the amount of cream filling or flavor, the cream almost always separated onto one wafer.

“We had expected an effect based on size,” Owens says. “If there was more cream between layers, it should be easier to deform. But that’s not actually the case.”

The researchers said the older boxed of Oreos seemed to spread more evenly than the newer ones. Owen’s said that if the inside of the Oreo cookies were more textured, the cream might grip better onto both sides and split more evenly when twister.